From a627614b58bbc6bde9cb1afabaebfbd629492723 Mon Sep 17 00:00:00 2001
From: Vojtech Bubnik <bubnikv@gmail.com>
Date: Wed, 4 May 2022 15:05:56 +0200
Subject: [PATCH] Perl unit tests for perimeters and multi-material were
 rewritten to C++. Perl binding was slimmed down, namely Clipper is no more
 linked by Perl.

---
 lib/Slic3r.pm                             |  83 ---
 lib/Slic3r/Config.pm                      |  41 --
 lib/Slic3r/ExPolygon.pm                   |   7 -
 lib/Slic3r/Geometry/Clipper.pm            |  13 -
 lib/Slic3r/Layer.pm                       |   3 -
 lib/Slic3r/Line.pm                        |   5 -
 lib/Slic3r/Model.pm                       |   7 -
 lib/Slic3r/Polygon.pm                     |   7 +-
 lib/Slic3r/Print/Object.pm                |   6 -
 lib/Slic3r/Print/State.pm                 |  12 -
 src/libslic3r/GCodeReader.cpp             |  64 ++-
 src/libslic3r/GCodeReader.hpp             |   2 +
 src/libslic3r/Polyline.cpp                |   2 +-
 src/libslic3r/Polyline.hpp                |   9 -
 src/libslic3r/PrintConfig.hpp             |  10 +
 src/libslic3r/Utils.hpp                   |  21 -
 src/libslic3r/utils.cpp                   |  63 ---
 t/dynamic.t                               |  93 ----
 t/geometry.t                              |   9 +-
 t/multi.t                                 | 221 --------
 t/perimeters.t                            | 444 ----------------
 t/slice.t                                 | 152 ------
 t/support.t                               | 272 ----------
 tests/fff_print/CMakeLists.txt            |   2 +
 tests/fff_print/test_extrusion_entity.cpp |   9 +-
 tests/fff_print/test_multi.cpp            | 268 ++++++++++
 tests/fff_print/test_perimeters.cpp       | 599 ++++++++++++++++++++++
 tests/fff_print/test_support_material.cpp | 259 ++++++++++
 tests/libslic3r/test_clipper_utils.cpp    |   5 +
 xs/CMakeLists.txt                         |   4 -
 xs/lib/Slic3r/XS.pm                       |  49 --
 xs/src/perlglue.cpp                       |   5 -
 xs/t/01_trianglemesh.t                    |   7 +-
 xs/t/13_polylinecollection.t              |  35 --
 xs/xsp/Clipper.xsp                        |  73 ---
 xs/xsp/Geometry.xsp                       |   8 -
 xs/xsp/Layer.xsp                          |  41 --
 xs/xsp/PerimeterGenerator.xsp             |  40 --
 xs/xsp/PlaceholderParser.xsp              |  33 --
 xs/xsp/Polygon.xsp                        |   1 -
 xs/xsp/Polyline.xsp                       |  14 -
 xs/xsp/PolylineCollection.xsp             |  81 ---
 xs/xsp/Print.xsp                          |  56 --
 xs/xsp/Surface.xsp                        |   1 -
 xs/xsp/TriangleMesh.xsp                   |  89 ----
 xs/xsp/XS.xsp                             | 127 +----
 xs/xsp/my.map                             | 113 ----
 xs/xsp/typemap.xspt                       |  39 --
 48 files changed, 1194 insertions(+), 2310 deletions(-)
 delete mode 100644 lib/Slic3r/Geometry/Clipper.pm
 delete mode 100644 lib/Slic3r/Print/State.pm
 delete mode 100644 t/dynamic.t
 delete mode 100644 t/multi.t
 delete mode 100644 t/perimeters.t
 delete mode 100644 t/slice.t
 delete mode 100644 t/support.t
 create mode 100644 tests/fff_print/test_multi.cpp
 create mode 100644 tests/fff_print/test_perimeters.cpp
 delete mode 100644 xs/t/13_polylinecollection.t
 delete mode 100644 xs/xsp/Clipper.xsp
 delete mode 100644 xs/xsp/PerimeterGenerator.xsp
 delete mode 100644 xs/xsp/PlaceholderParser.xsp
 delete mode 100644 xs/xsp/PolylineCollection.xsp

diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index d9274bea9..cd8f151f8 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -28,11 +28,6 @@ BEGIN {
 
 use FindBin;
 
-# Let the XS module know where the GUI resources reside.
-set_resources_dir(decode_path($FindBin::Bin) . (($^O eq 'darwin') ? '/../Resources' : '/resources'));
-set_var_dir(resources_dir() . "/icons");
-set_local_dir(resources_dir() . "/localization/");
-
 use Moo 1.003001;
 
 use Slic3r::XS;   # import all symbols (constants etc.) before they get parsed
@@ -60,82 +55,4 @@ use constant SCALING_FACTOR         => 0.000001;
 $Slic3r::loglevel = (defined($ENV{'SLIC3R_LOGLEVEL'}) && $ENV{'SLIC3R_LOGLEVEL'} =~ /^[1-9]/) ? $ENV{'SLIC3R_LOGLEVEL'} : 0;
 set_logging_level($Slic3r::loglevel);
 
-# Let the palceholder parser evaluate one expression to initialize its local static macro_processor 
-# class instance in a thread safe manner.
-Slic3r::GCode::PlaceholderParser->new->evaluate_boolean_expression('1==1');
-
-# Open a file by converting $filename to local file system locales.
-sub open {
-    my ($fh, $mode, $filename) = @_;
-    return CORE::open $$fh, $mode, encode_path($filename);
-}
-
-sub tags {
-    my ($format) = @_;
-    $format //= '';
-    my %tags;
-    # End of line
-    $tags{eol}     = ($format eq 'html') ? '<br>'   : "\n";
-    # Heading
-    $tags{h2start} = ($format eq 'html') ? '<b>'   : '';
-    $tags{h2end}   = ($format eq 'html') ? '</b>'  : '';
-    # Bold font
-    $tags{bstart}  = ($format eq 'html') ? '<b>'    : '';
-    $tags{bend}    = ($format eq 'html') ? '</b>'   : '';
-    # Verbatim
-    $tags{vstart}  = ($format eq 'html') ? '<pre>'  : '';
-    $tags{vend}    = ($format eq 'html') ? '</pre>' : '';
-    return %tags;
-}
-
-sub slic3r_info
-{
-    my (%params) = @_;
-    my %tag = Slic3r::tags($params{format});
-    my $out = '';
-    $out .= "$tag{bstart}$Slic3r::FORK_NAME$tag{bend}$tag{eol}";
-    $out .= "$tag{bstart}Version: $tag{bend}$Slic3r::VERSION$tag{eol}";
-    $out .= "$tag{bstart}Build:   $tag{bend}$Slic3r::BUILD$tag{eol}";
-    return $out;
-}
-
-sub copyright_info
-{
-    my (%params) = @_;
-    my %tag = Slic3r::tags($params{format});
-    my $out =
-        'Copyright &copy; 2016 Vojtech Bubnik, Prusa Research. <br />' .
-        'Copyright &copy; 2011-2016 Alessandro Ranellucci. <br />' .
-        '<a href="http://slic3r.org/">Slic3r</a> is licensed under the ' .
-        '<a href="http://www.gnu.org/licenses/agpl-3.0.html">GNU Affero General Public License, version 3</a>.' .
-        '<br /><br /><br />' .
-        'Contributions by Henrik Brix Andersen, Nicolas Dandrimont, Mark Hindess, Petr Ledvina, Y. Sapir, Mike Sheldrake and numerous others. ' .
-        'Manual by Gary Hodgson. Inspired by the RepRap community. <br />' .
-        'Slic3r logo designed by Corey Daniels, <a href="http://www.famfamfam.com/lab/icons/silk/">Silk Icon Set</a> designed by Mark James. ';
-    return $out;
-}
-
-sub system_info
-{
-    my (%params) = @_;
-    my %tag = Slic3r::tags($params{format});
-
-    my $out = '';
-    $out .= "$tag{bstart}Operating System:    $tag{bend}$Config{osname}$tag{eol}";
-    $out .= "$tag{bstart}System Architecture: $tag{bend}$Config{archname}$tag{eol}";        
-    if ($^O eq 'MSWin32') {
-        $out .= "$tag{bstart}Windows Version: $tag{bend}" . `ver` . $tag{eol};
-    } else {
-        # Hopefully some kind of unix / linux.
-        $out .= "$tag{bstart}System Version: $tag{bend}" . `uname -a` . $tag{eol};
-    }
-    $out .= $tag{vstart} . Config::myconfig . $tag{vend};
-    $out .= "  $tag{bstart}\@INC:$tag{bend}$tag{eol}$tag{vstart}";
-    foreach my $i (@INC) {
-        $out .= "    $i\n";
-    }
-    $out .= "$tag{vend}";
-    return $out;
-}
-
 1;
diff --git a/lib/Slic3r/Config.pm b/lib/Slic3r/Config.pm
index a9c822b96..aeaca998f 100644
--- a/lib/Slic3r/Config.pm
+++ b/lib/Slic3r/Config.pm
@@ -23,47 +23,6 @@ our $Options = print_config_def();
     }
 }
 
-# From command line parameters, used by slic3r.pl
-sub new_from_cli {
-    my $class = shift;
-    my %args = @_;
-    
-    # Delete hash keys with undefined value.
-    delete $args{$_} for grep !defined $args{$_}, keys %args;
-    
-    # Replace the start_gcode, end_gcode ... hash values
-    # with the content of the files they reference.
-    for (qw(start end layer toolchange)) {
-        my $opt_key = "${_}_gcode";
-        if ($args{$opt_key}) {
-            if (-e $args{$opt_key}) {
-                Slic3r::open(\my $fh, "<", $args{$opt_key})
-                    or die "Failed to open $args{$opt_key}\n";
-                binmode $fh, ':utf8';
-                $args{$opt_key} = do { local $/; <$fh> };
-                close $fh;
-            }
-        }
-    }
-
-    my $self = $class->new;
-    foreach my $opt_key (keys %args) {
-        my $opt_def = $Options->{$opt_key};
-        
-        # we use set_deserialize() for bool options since GetOpt::Long doesn't handle 
-        # arrays of boolean values
-        if ($opt_key =~ /^(?:bed_shape|duplicate_grid|extruder_offset)$/ || $opt_def->{type} eq 'bool') {
-            $self->set_deserialize($opt_key, $args{$opt_key});
-        } elsif (my $shortcut = $opt_def->{shortcut}) {
-            $self->set($_, $args{$opt_key}) for @$shortcut;
-        } else {
-            $self->set($opt_key, $args{$opt_key});
-        }
-    }
-    
-    return $self;
-}
-
 package Slic3r::Config::Static;
 use parent 'Slic3r::Config';
 
diff --git a/lib/Slic3r/ExPolygon.pm b/lib/Slic3r/ExPolygon.pm
index 4ab1bc8ab..6090a073b 100644
--- a/lib/Slic3r/ExPolygon.pm
+++ b/lib/Slic3r/ExPolygon.pm
@@ -4,13 +4,6 @@ use warnings;
 
 # an ExPolygon is a polygon with holes
 
-sub noncollapsing_offset_ex {
-    my $self = shift;
-    my ($distance, @params) = @_;
-    
-    return $self->offset_ex($distance + 1, @params);
-}
-
 sub bounding_box {
     my $self = shift;
     return $self->contour->bounding_box;
diff --git a/lib/Slic3r/Geometry/Clipper.pm b/lib/Slic3r/Geometry/Clipper.pm
deleted file mode 100644
index c1fa81d9f..000000000
--- a/lib/Slic3r/Geometry/Clipper.pm
+++ /dev/null
@@ -1,13 +0,0 @@
-package Slic3r::Geometry::Clipper;
-use strict;
-use warnings;
-
-require Exporter;
-our @ISA = qw(Exporter);
-our @EXPORT_OK = qw(
-	offset 
-	offset2_ex
-    diff_ex diff union_ex 
-    union);
-
-1;
diff --git a/lib/Slic3r/Layer.pm b/lib/Slic3r/Layer.pm
index 4bff9b61f..7f7b589d0 100644
--- a/lib/Slic3r/Layer.pm
+++ b/lib/Slic3r/Layer.pm
@@ -31,7 +31,4 @@ sub regions {
     return [ map $self->get_region($_), 0..($self->region_count-1) ];
 }
 
-package Slic3r::Layer::Support;
-our @ISA = qw(Slic3r::Layer);
-
 1;
diff --git a/lib/Slic3r/Line.pm b/lib/Slic3r/Line.pm
index c06f9a1fa..16b609c95 100644
--- a/lib/Slic3r/Line.pm
+++ b/lib/Slic3r/Line.pm
@@ -5,9 +5,4 @@ use warnings;
 # a line is a two-points line
 use parent 'Slic3r::Polyline';
 
-sub grow {
-    my $self = shift;
-    return Slic3r::Polyline->new(@$self)->grow(@_);
-}
-
 1;
diff --git a/lib/Slic3r/Model.pm b/lib/Slic3r/Model.pm
index ec31f6c8a..d44e9878d 100644
--- a/lib/Slic3r/Model.pm
+++ b/lib/Slic3r/Model.pm
@@ -133,11 +133,4 @@ sub add_instance {
     }
 }
 
-sub mesh_stats {
-    my $self = shift;
-    
-    # TODO: sum values from all volumes
-    return $self->volumes->[0]->mesh->stats;
-}
-
 1;
diff --git a/lib/Slic3r/Polygon.pm b/lib/Slic3r/Polygon.pm
index 16222141a..d5445047d 100644
--- a/lib/Slic3r/Polygon.pm
+++ b/lib/Slic3r/Polygon.pm
@@ -5,9 +5,4 @@ use warnings;
 # a polygon is a closed polyline.
 use parent 'Slic3r::Polyline';
 
-sub grow {
-    my $self = shift;
-    return $self->split_at_first_point->grow(@_);
-}
-
-1;
\ No newline at end of file
+1;
diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index 64480e08f..35da7afe7 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -5,7 +5,6 @@ use warnings;
 
 use List::Util qw(min max sum first);
 use Slic3r::Flow ':roles';
-use Slic3r::Print::State ':steps';
 use Slic3r::Surface ':types';
 
 sub layers {
@@ -13,9 +12,4 @@ sub layers {
     return [ map $self->get_layer($_), 0..($self->layer_count - 1) ];
 }
 
-sub support_layers {
-    my $self = shift;
-    return [ map $self->get_support_layer($_), 0..($self->support_layer_count - 1) ];
-}
-
 1;
diff --git a/lib/Slic3r/Print/State.pm b/lib/Slic3r/Print/State.pm
deleted file mode 100644
index 17c614f1b..000000000
--- a/lib/Slic3r/Print/State.pm
+++ /dev/null
@@ -1,12 +0,0 @@
-# Wraps C++ enums Slic3r::PrintStep and Slic3r::PrintObjectStep
-package Slic3r::Print::State;
-use strict;
-use warnings;
-
-require Exporter;
-our @ISA = qw(Exporter);
-our @EXPORT_OK   = qw(STEP_SLICE STEP_PERIMETERS STEP_PREPARE_INFILL 
-                    STEP_INFILL STEP_SUPPORTMATERIAL STEP_SKIRT STEP_BRIM STEP_WIPE_TOWER);
-our %EXPORT_TAGS = (steps => \@EXPORT_OK);
-
-1;
diff --git a/src/libslic3r/GCodeReader.cpp b/src/libslic3r/GCodeReader.cpp
index c8a9b790f..44b0b89f6 100644
--- a/src/libslic3r/GCodeReader.cpp
+++ b/src/libslic3r/GCodeReader.cpp
@@ -215,9 +215,9 @@ bool GCodeReader::parse_file_raw(const std::string &filename, raw_line_callback_
         [](size_t){});
 }
 
-bool GCodeReader::GCodeLine::has(char axis) const
+const char* GCodeReader::axis_pos(const char *raw_str, char axis)
 {
-    const char *c = m_raw.c_str();
+    const char *c = raw_str;
     // Skip the whitespaces.
     c = skip_whitespaces(c);
     // Skip the command.
@@ -230,40 +230,48 @@ bool GCodeReader::GCodeLine::has(char axis) const
             break;
         // Check the name of the axis.
         if (*c == axis)
-            return true;
+            return c;
         // Skip the rest of the word.
         c = skip_word(c);
     }
-    return false;
+    return nullptr;
+}
+
+bool GCodeReader::GCodeLine::has(char axis) const
+{
+    const char *c = axis_pos(m_raw.c_str(), axis);
+    return c != nullptr;
 }
 
 bool GCodeReader::GCodeLine::has_value(char axis, float &value) const
 {
     assert(is_decimal_separator_point());
-    const char *c = m_raw.c_str();
-    // Skip the whitespaces.
-    c = skip_whitespaces(c);
-    // Skip the command.
-    c = skip_word(c);
-    // Up to the end of line or comment.
-    while (! is_end_of_gcode_line(*c)) {
-        // Skip whitespaces.
-        c = skip_whitespaces(c);
-        if (is_end_of_gcode_line(*c))
-            break;
-        // Check the name of the axis.
-        if (*c == axis) {
-            // Try to parse the numeric value.
-            char   *pend = nullptr;
-            double  v = strtod(++ c, &pend);
-            if (pend != nullptr && is_end_of_word(*pend)) {
-                // The axis value has been parsed correctly.
-                value = float(v);
-                return true;
-            }
-        }
-        // Skip the rest of the word.
-        c = skip_word(c);
+    const char *c = axis_pos(m_raw.c_str(), axis);
+    if (c == nullptr)
+        return false;
+    // Try to parse the numeric value.
+    char   *pend = nullptr;
+    double  v = strtod(++ c, &pend);
+    if (pend != nullptr && is_end_of_word(*pend)) {
+        // The axis value has been parsed correctly.
+        value = float(v);
+        return true;
+    }
+    return false;
+}
+
+bool GCodeReader::GCodeLine::has_value(char axis, int &value) const
+{
+    const char *c = axis_pos(m_raw.c_str(), axis);
+    if (c == nullptr)
+        return false;
+    // Try to parse the numeric value.
+    char   *pend = nullptr;
+    long    v = strtol(++ c, &pend, 10);
+    if (pend != nullptr && is_end_of_word(*pend)) {
+        // The axis value has been parsed correctly.
+        value = int(v);
+        return true;
     }
     return false;
 }
diff --git a/src/libslic3r/GCodeReader.hpp b/src/libslic3r/GCodeReader.hpp
index 40a099229..25ba6ee0b 100644
--- a/src/libslic3r/GCodeReader.hpp
+++ b/src/libslic3r/GCodeReader.hpp
@@ -30,6 +30,7 @@ public:
         float value(Axis axis) const { return m_axis[axis]; }
         bool  has(char axis) const;
         bool  has_value(char axis, float &value) const;
+        bool  has_value(char axis, int &value) const;
         float new_X(const GCodeReader &reader) const { return this->has(X) ? this->x() : reader.x(); }
         float new_Y(const GCodeReader &reader) const { return this->has(Y) ? this->y() : reader.y(); }
         float new_Z(const GCodeReader &reader) const { return this->has(Z) ? this->z() : reader.z(); }
@@ -166,6 +167,7 @@ private:
             ; // silence -Wempty-body
         return c;
     }
+    static const char*  axis_pos(const char *raw_str, char axis);
 
     GCodeConfig m_config;
     char        m_extrusion_axis;
diff --git a/src/libslic3r/Polyline.cpp b/src/libslic3r/Polyline.cpp
index 1255d5473..43c5afe73 100644
--- a/src/libslic3r/Polyline.cpp
+++ b/src/libslic3r/Polyline.cpp
@@ -196,7 +196,7 @@ BoundingBox get_extents(const Polylines &polylines)
 const Point& leftmost_point(const Polylines &polylines)
 {
     if (polylines.empty())
-        throw Slic3r::InvalidArgument("leftmost_point() called on empty PolylineCollection");
+        throw Slic3r::InvalidArgument("leftmost_point() called on empty Polylines");
     Polylines::const_iterator it = polylines.begin();
     const Point *p = &it->leftmost_point();
     for (++ it; it != polylines.end(); ++it) {
diff --git a/src/libslic3r/Polyline.hpp b/src/libslic3r/Polyline.hpp
index 256dca28c..e0379e869 100644
--- a/src/libslic3r/Polyline.hpp
+++ b/src/libslic3r/Polyline.hpp
@@ -80,15 +80,6 @@ public:
 inline bool operator==(const Polyline &lhs, const Polyline &rhs) { return lhs.points == rhs.points; }
 inline bool operator!=(const Polyline &lhs, const Polyline &rhs) { return lhs.points != rhs.points; }
 
-// Don't use this class in production code, it is used exclusively by the Perl binding for unit tests!
-#ifdef PERL_UCHAR_MIN
-class PolylineCollection
-{
-public:
-    Polylines polylines;
-};
-#endif /* PERL_UCHAR_MIN */
-
 extern BoundingBox get_extents(const Polyline &polyline);
 extern BoundingBox get_extents(const Polylines &polylines);
 
diff --git a/src/libslic3r/PrintConfig.hpp b/src/libslic3r/PrintConfig.hpp
index 950816fa9..be2e2dbef 100644
--- a/src/libslic3r/PrintConfig.hpp
+++ b/src/libslic3r/PrintConfig.hpp
@@ -211,6 +211,16 @@ public:
     DynamicPrintConfig& operator=(DynamicPrintConfig &&rhs) noexcept { DynamicConfig::operator=(std::move(rhs)); return *this; }
 
     static DynamicPrintConfig  full_print_config();
+    static DynamicPrintConfig  full_print_config_with(const t_config_option_key &opt_key, const std::string &str, bool append = false) {
+        auto config = DynamicPrintConfig::full_print_config();
+        config.set_deserialize_strict(opt_key, str, append);
+        return config;
+    }
+    static DynamicPrintConfig  full_print_config_with(std::initializer_list<SetDeserializeItem> items) {
+        auto config = DynamicPrintConfig::full_print_config();
+        config.set_deserialize_strict(items);
+        return config;
+    }
     static DynamicPrintConfig* new_from_defaults_keys(const std::vector<std::string> &keys);
 
     // Overrides ConfigBase::def(). Static configuration definition. Any value stored into this ConfigBase shall have its definition here.
diff --git a/src/libslic3r/Utils.hpp b/src/libslic3r/Utils.hpp
index 10790ef49..6a09e7fbf 100644
--- a/src/libslic3r/Utils.hpp
+++ b/src/libslic3r/Utils.hpp
@@ -18,7 +18,6 @@ namespace Slic3r {
 
 extern void set_logging_level(unsigned int level);
 extern unsigned get_logging_level();
-extern void trace(unsigned int level, const char *message);
 // Format memory allocated, separate thousands by comma.
 extern std::string format_memsize_MB(size_t n);
 // Return string to be added to the boost::log output to inform about the current process memory allocation.
@@ -68,13 +67,6 @@ std::string debug_out_path(const char *name, ...);
 // This type is only needed for Perl bindings to relay to Perl that the string is raw, not UTF-8 encoded.
 typedef std::string local_encoded_string;
 
-// Convert an UTF-8 encoded string into local coding.
-// On Windows, the UTF-8 string is converted to a local 8-bit code page.
-// On OSX and Linux, this function does no conversion and returns a copy of the source string.
-extern local_encoded_string encode_path(const char *src);
-extern std::string decode_path(const char *src);
-extern std::string normalize_utf8_nfc(const char *src);
-
 // Returns next utf8 sequence length. =number of bytes in string, that creates together one utf-8 character. 
 // Starting at pos. ASCII characters returns 1. Works also if pos is in the middle of the sequence.
 extern size_t get_utf8_sequence_length(const std::string& text, size_t pos = 0);
@@ -115,19 +107,6 @@ extern bool is_gallery_file(const boost::filesystem::directory_entry& path, char
 extern bool is_gallery_file(const std::string& path, char const* type);
 extern bool is_shapes_dir(const std::string& dir);
 
-// File path / name / extension splitting utilities, working with UTF-8,
-// to be published to Perl.
-namespace PerlUtils {
-    // Get a file name including the extension.
-    extern std::string path_to_filename(const char *src);
-    // Get a file name without the extension.
-    extern std::string path_to_stem(const char *src);
-    // Get just the extension.
-    extern std::string path_to_extension(const char *src);
-    // Get a directory without the trailing slash.
-    extern std::string path_to_parent_path(const char *src);
-};
-
 std::string string_printf(const char *format, ...);
 
 // Standard "generated by Slic3r version xxx timestamp xxx" header string, 
diff --git a/src/libslic3r/utils.cpp b/src/libslic3r/utils.cpp
index ddc9a4081..371b8eb11 100644
--- a/src/libslic3r/utils.cpp
+++ b/src/libslic3r/utils.cpp
@@ -125,14 +125,6 @@ static struct RunOnInit {
     }
 } g_RunOnInit;
 
-void trace(unsigned int level, const char *message)
-{
-    boost::log::trivial::severity_level severity = level_to_boost(level);
-
-    BOOST_LOG_STREAM_WITH_PARAMS(::boost::log::trivial::logger::get(),\
-        (::boost::log::keywords::severity = severity)) << message;
-}
-
 void disable_multi_threading()
 {
     // Disable parallelization so the Shiny profiler works
@@ -820,49 +812,6 @@ bool is_shapes_dir(const std::string& dir)
 
 namespace Slic3r {
 
-// Encode an UTF-8 string to the local code page.
-std::string encode_path(const char *src)
-{    
-#ifdef WIN32
-    // Convert the source utf8 encoded string to a wide string.
-    std::wstring wstr_src = boost::nowide::widen(src);
-    if (wstr_src.length() == 0)
-        return std::string();
-    // Convert a wide string to a local code page.
-    int size_needed = ::WideCharToMultiByte(0, 0, wstr_src.data(), (int)wstr_src.size(), nullptr, 0, nullptr, nullptr);
-    std::string str_dst(size_needed, 0);
-    ::WideCharToMultiByte(0, 0, wstr_src.data(), (int)wstr_src.size(), str_dst.data(), size_needed, nullptr, nullptr);
-    return str_dst;
-#else /* WIN32 */
-    return src;
-#endif /* WIN32 */
-}
-
-// Encode an 8-bit string from a local code page to UTF-8.
-// Multibyte to utf8
-std::string decode_path(const char *src)
-{  
-#ifdef WIN32
-    int len = int(strlen(src));
-    if (len == 0)
-        return std::string();
-    // Convert the string encoded using the local code page to a wide string.
-    int size_needed = ::MultiByteToWideChar(0, 0, src, len, nullptr, 0);
-    std::wstring wstr_dst(size_needed, 0);
-    ::MultiByteToWideChar(0, 0, src, len, wstr_dst.data(), size_needed);
-    // Convert a wide string to utf8.
-    return boost::nowide::narrow(wstr_dst.c_str());
-#else /* WIN32 */
-    return src;
-#endif /* WIN32 */
-}
-
-std::string normalize_utf8_nfc(const char *src)
-{
-    static std::locale locale_utf8(boost::locale::generator().generate(""));
-    return boost::locale::normalize(src, boost::locale::norm_nfc, locale_utf8);
-}
-
 size_t get_utf8_sequence_length(const std::string& text, size_t pos)
 {
 	assert(pos < text.size());
@@ -933,18 +882,6 @@ size_t get_utf8_sequence_length(const char *seq, size_t size)
 	return length;
 }
 
-namespace PerlUtils {
-    // Get a file name including the extension.
-    std::string path_to_filename(const char *src)       { return boost::filesystem::path(src).filename().string(); }
-    // Get a file name without the extension.
-    std::string path_to_stem(const char *src)           { return boost::filesystem::path(src).stem().string(); }
-    // Get just the extension.
-    std::string path_to_extension(const char *src)      { return boost::filesystem::path(src).extension().string(); }
-    // Get a directory without the trailing slash.
-    std::string path_to_parent_path(const char *src)    { return boost::filesystem::path(src).parent_path().string(); }
-};
-
-
 std::string string_printf(const char *format, ...)
 {
     va_list args1;
diff --git a/t/dynamic.t b/t/dynamic.t
deleted file mode 100644
index 5d4d3ceb4..000000000
--- a/t/dynamic.t
+++ /dev/null
@@ -1,93 +0,0 @@
-use Test::More;
-use strict;
-use warnings;
-
-plan skip_all => 'variable-width paths are currently disabled';
-plan tests => 20;
-
-BEGIN {
-    use FindBin;
-    use lib "$FindBin::Bin/../lib";
-    use local::lib "$FindBin::Bin/../local-lib";
-}
-
-use List::Util qw(first);
-use Slic3r;
-use Slic3r::Geometry qw(X Y scale epsilon);
-use Slic3r::Surface ':types';
-
-sub scale_points (@) { map [scale $_->[X], scale $_->[Y]], @_ }
-
-{
-    my $square = Slic3r::ExPolygon->new([
-        scale_points [0,0], [10,0], [10,10], [0,10],
-    ]);
-    
-    my @offsets = @{$square->noncollapsing_offset_ex(- scale 5)};
-    is scalar @offsets, 1, 'non-collapsing offset';
-}
-
-{
-    local $Slic3r::Config = Slic3r::Config->new(
-        perimeters      => 3,
-    );
-    my $w = 0.7;
-    my $perimeter_flow = Slic3r::Flow->new(
-        nozzle_diameter => 0.5,
-        layer_height    => 0.4,
-        width           => $w,
-    );
-    
-    my $print = Slic3r::Print->new;
-    my $region = Slic3r::Print::Region->new(
-        print => $print,
-        flows => { perimeter => $perimeter_flow },
-    );
-    push @{$print->regions}, $region;
-    my $object = Slic3r::Print::Object->new(
-        print => $print,
-        size  => [1,1],
-    );
-    my $make_layer = sub {
-        my ($width) = @_;
-        my $layer = Slic3r::Layer->new(
-            object => $object,
-            id => 1,
-            slices => [
-                Slic3r::Surface->new(
-                    surface_type    => S_TYPE_INTERNAL,
-                    expolygon       => Slic3r::ExPolygon->new([ scale_points [0,0], [50,0], [50,$width], [0,$width] ]),
-                ),
-            ],
-            thin_walls => [],
-        );
-        my $layerm = $layer->region(0);
-        $layer->make_perimeters;
-        return $layerm;
-    };
-    
-    my %widths = (
-        1   * $w => { perimeters => 1, gaps => 0 },
-        1.3 * $w => { perimeters => 1, gaps => 1, gap_flow_spacing => $perimeter_flow->clone(width => 0.2 * $w)->spacing },
-        1.5 * $w => { perimeters => 1, gaps => 1, gap_flow_spacing => $perimeter_flow->clone(width => 0.5 * $w)->spacing },
-        2   * $w => { perimeters => 1, gaps => 1, gap_flow_spacing => $perimeter_flow->spacing },
-        2.5 * $w => { perimeters => 1, gaps => 1, gap_flow_spacing => $perimeter_flow->clone(width => 1.5 * $w)->spacing },
-        3   * $w => { perimeters => 2, gaps => 0 },
-        4   * $w => { perimeters => 2, gaps => 1, gap_flow_spacing => $perimeter_flow->spacing },
-    );
-    
-    foreach my $width (sort keys %widths) {
-        my $layerm = $make_layer->($width);
-        is scalar @{$layerm->perimeters}, $widths{$width}{perimeters}, 'right number of perimeters';
-        is scalar @{$layerm->thin_fills} ? 1 : 0, $widths{$width}{gaps},
-            ($widths{$width}{gaps} ? 'gaps were filled' : 'no gaps detected');  # TODO: we should check the exact number of gaps, but we need a better medial axis algorithm
-        
-        my @gaps = map $_, @{$layerm->thin_fills};
-        if (@gaps) {
-            ok +(!first { abs($_->flow_spacing - $widths{$width}{gap_flow_spacing}) > epsilon } @gaps),
-                'flow spacing was dynamically adjusted';
-        }
-    }
-}
-
-__END__
diff --git a/t/geometry.t b/t/geometry.t
index 874dab987..12a1ca743 100644
--- a/t/geometry.t
+++ b/t/geometry.t
@@ -2,7 +2,7 @@ use Test::More;
 use strict;
 use warnings;
 
-plan tests => 27;
+plan tests => 26;
 
 BEGIN {
     use FindBin;
@@ -125,13 +125,6 @@ my $polygons = [
 
 #==========================================================
 
-{
-    my $line = Slic3r::Line->new([10,10], [20,10]);
-    is $line->grow(5)->[0]->area, Slic3r::Polygon->new([10,5], [20,5], [20,15], [10,15])->area, 'grow line';
-}
-
-#==========================================================
-
 {
     # if chained_path() works correctly, these points should be joined with no diagonal paths
     # (thus 26 units long)
diff --git a/t/multi.t b/t/multi.t
deleted file mode 100644
index e74a7a1a8..000000000
--- a/t/multi.t
+++ /dev/null
@@ -1,221 +0,0 @@
-use Test::More tests => 13;
-use strict;
-use warnings;
-
-BEGIN {
-    use FindBin;
-    use lib "$FindBin::Bin/../lib";
-    use local::lib "$FindBin::Bin/../local-lib";
-}
-
-use List::Util qw(first);
-use Slic3r;
-use Slic3r::Geometry qw(scale convex_hull);
-use Slic3r::Geometry::Clipper qw(offset);
-use Slic3r::Test;
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('nozzle_diameter', [0.6,0.6,0.6,0.6]);
-    $config->set('raft_layers', 2);
-    $config->set('infill_extruder', 2);
-    $config->set('solid_infill_extruder', 3);
-    $config->set('support_material_extruder', 4);
-    $config->set('ooze_prevention', 1);
-    $config->set('extruder_offset', [ [0,0], [20,0], [0,20], [20,20] ]);
-    $config->set('temperature', [200, 180, 170, 160]);
-    $config->set('first_layer_temperature', [206, 186, 166, 156]);
-    $config->set('toolchange_gcode', 'T[next_extruder] ;toolchange');  # test that it doesn't crash when this is supplied
-    # Since July 2019, PrusaSlicer only emits automatic Tn command in case that the toolchange_gcode is empty
-    # The "T[next_extruder]" is therefore needed in this test.
-    
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    
-    my $tool = undef;
-    my @tool_temp = (0,0,0,0);
-    my @toolchange_points = ();
-    my @extrusion_points = ();
-    Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-        my ($self, $cmd, $args, $info) = @_;
-        
-        if ($cmd =~ /^T(\d+)/) {
-            # ignore initial toolchange
-            if (defined $tool) {
-                my $expected_temp = $self->Z == ($config->get_value('first_layer_height') + $config->z_offset)
-                    ? $config->first_layer_temperature->[$tool]
-                    : $config->temperature->[$tool];
-                die 'standby temperature was not set before toolchange'
-                    if $tool_temp[$tool] != $expected_temp + $config->standby_temperature_delta;
-                
-                push @toolchange_points, my $point = Slic3r::Point->new_scale($self->X, $self->Y);
-            }
-            $tool = $1;
-        } elsif ($cmd eq 'M104' || $cmd eq 'M109') {
-            my $t = $args->{T} // $tool;
-            if ($tool_temp[$t] == 0) {
-                fail 'initial temperature is not equal to first layer temperature + standby delta'
-                    unless $args->{S} == $config->first_layer_temperature->[$t] + $config->standby_temperature_delta;
-            }
-            $tool_temp[$t] = $args->{S};
-        } elsif ($cmd eq 'G1' && $info->{extruding} && $info->{dist_XY} > 0) {
-            push @extrusion_points, my $point = Slic3r::Point->new_scale($args->{X}, $args->{Y});
-            $point->translate(map +scale($_), @{ $config->extruder_offset->[$tool] });
-        }
-    });
-    my $convex_hull = convex_hull(\@extrusion_points);
-    
-    my @t = ();
-    foreach my $point (@toolchange_points) {
-        foreach my $offset (@{$config->extruder_offset}) {
-            push @t, my $p = $point->clone;
-            $p->translate(map +scale($_), @$offset);
-        }
-    }
-    ok !(defined first { $convex_hull->contains_point($_) } @t), 'all nozzles are outside skirt at toolchange';
-    
-    if (0) {
-        require "Slic3r/SVG.pm";
-        Slic3r::SVG::output(
-            "ooze_prevention_test.svg",
-            no_arrows   => 1,
-            polygons    => [$convex_hull],
-            red_points  => \@t,
-            points      => \@toolchange_points,
-        );
-    }
-    
-    # offset the skirt by the maximum displacement between extruders plus a safety extra margin
-    my $delta = scale(20 * sqrt(2) + 1);
-    my $outer_convex_hull = offset([$convex_hull], +$delta)->[0];
-    ok !(defined first { !$outer_convex_hull->contains_point($_) } @toolchange_points), 'all toolchanges happen within expected area';
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('nozzle_diameter', [0.6,0.6,0.6,0.6]);
-    $config->set('support_material_extruder', 3);
-    
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    ok Slic3r::Test::gcode($print), 'no errors when using non-consecutive extruders';
-}
-
-{
-    my $config = Slic3r::Config->new;
-    $config->set('nozzle_diameter', [0.6,0.6,0.6,0.6]);
-    $config->set('extruder', 2);
-    
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    like Slic3r::Test::gcode($print), qr/ T1/, 'extruder shortcut';
-}
-
-{
-    my $config = Slic3r::Config->new;
-    $config->set('nozzle_diameter', [0.6,0.6,0.6,0.6]);
-    $config->set('perimeter_extruder', 2);
-    $config->set('infill_extruder', 2);
-    $config->set('support_material_extruder', 2);
-    $config->set('support_material_interface_extruder', 2);
-    
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    ok Slic3r::Test::gcode($print), 'no errors when using multiple skirts with a single, non-zero, extruder';
-}
-
-{
-    my $model = stacked_cubes();
-    my $lower_config = $model->get_material('lower')->config;
-    my $upper_config = $model->get_material('upper')->config;
-    
-    $lower_config->set('extruder', 1);
-    $lower_config->set('bottom_solid_layers', 0);
-    $lower_config->set('top_solid_layers', 1);
-    $upper_config->set('extruder', 2);
-    $upper_config->set('bottom_solid_layers', 1);
-    $upper_config->set('top_solid_layers', 0);
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('nozzle_diameter', [0.6,0.6,0.6,0.6]);
-    $config->set('fill_density', 0);
-    $config->set('solid_infill_speed', 99);
-    $config->set('top_solid_infill_speed', 99);
-    $config->set('cooling', [ 0 ]);             # for preventing speeds from being altered
-    $config->set('first_layer_speed', '100%');  # for preventing speeds from being altered
-    
-    my $test = sub {
-        my $print = Slic3r::Test::init_print($model, config => $config);
-        my $tool = undef;
-        my %T0_shells = my %T1_shells = ();  # Z => 1
-        Slic3r::GCode::Reader->new->parse(my $gcode = Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-        
-            if ($cmd =~ /^T(\d+)/) {
-                $tool = $1;
-            } elsif ($cmd eq 'G1' && $info->{extruding} && $info->{dist_XY} > 0) {
-                if (($args->{F} // $self->F) == $config->solid_infill_speed*60) {
-                    if ($tool == 0) {
-                        $T0_shells{$self->Z} = 1;
-                    } elsif ($tool == 1) {
-                        $T1_shells{$self->Z} = 1;
-                    }
-                }
-            }
-        });
-        return [ sort keys %T0_shells ], [ sort keys %T1_shells ];
-    };
-    
-    {
-        my ($t0, $t1) = $test->();
-        is scalar(@$t0), 0, 'no interface shells';
-        is scalar(@$t1), 0, 'no interface shells';
-    }
-    {
-        $config->set('interface_shells', 1);
-        my ($t0, $t1) = $test->();
-        is scalar(@$t0), $lower_config->top_solid_layers,    'top interface shells';
-        is scalar(@$t1), $upper_config->bottom_solid_layers, 'bottom interface shells';
-    }
-}
-
-{
-    my $model = stacked_cubes();
-    my $object = $model->objects->[0];
-    
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('nozzle_diameter', [0.6,0.6,0.6,0.6]);
-    $config->set('layer_height', 0.4);
-    $config->set('first_layer_height', $config->layer_height);
-    $config->set('skirts', 0);
-    my $print = Slic3r::Test::init_print($model, config => $config);
-    
-    is $object->volumes->[0]->config->extruder, 1, 'auto_assign_extruders() assigned correct extruder to first volume';
-    is $object->volumes->[1]->config->extruder, 2, 'auto_assign_extruders() assigned correct extruder to second volume';
-    
-    my $tool = undef;
-    my %T0 = my %T1 = ();  # Z => 1
-    Slic3r::GCode::Reader->new->parse(my $gcode = Slic3r::Test::gcode($print), sub {
-        my ($self, $cmd, $args, $info) = @_;
-    
-        if ($cmd =~ /^T(\d+)/) {
-            $tool = $1;
-        } elsif ($cmd eq 'G1' && $info->{extruding} && $info->{dist_XY} > 0) {
-            if ($tool == 0) {
-                $T0{$self->Z} = 1;
-            } elsif ($tool == 1) {
-                $T1{$self->Z} = 1;
-            }
-        }
-    });
-    
-    ok !(defined first { $_ > 20 } keys %T0), 'T0 is never used for upper object';
-    ok !(defined first { $_ < 20 } keys %T1), 'T1 is never used for lower object';
-}
-
-sub stacked_cubes {
-    my $model = Slic3r::Model->new;
-    my $object = $model->add_object;
-    $object->add_volume(mesh => Slic3r::Test::mesh('20mm_cube'), material_id => 'lower');
-    $object->add_volume(mesh => Slic3r::Test::mesh('20mm_cube', translate => [0,0,20]), material_id => 'upper');
-    $object->add_instance(offset => Slic3r::Pointf->new(0,0));
-    
-    return $model;
-}
-
-__END__
diff --git a/t/perimeters.t b/t/perimeters.t
deleted file mode 100644
index c4aef6e7e..000000000
--- a/t/perimeters.t
+++ /dev/null
@@ -1,444 +0,0 @@
-use Test::More tests => 59;
-use strict;
-use warnings;
-
-BEGIN {
-    use FindBin;
-    use lib "$FindBin::Bin/../lib";
-    use local::lib "$FindBin::Bin/../local-lib";
-}
-
-use Slic3r::ExtrusionLoop ':roles';
-use Slic3r::ExtrusionPath ':roles';
-use List::Util qw(first);
-use Slic3r;
-use Slic3r::Flow ':roles';
-use Slic3r::Geometry qw(PI scale unscale);
-use Slic3r::Geometry::Clipper qw(union_ex diff);
-use Slic3r::Surface ':types';
-use Slic3r::Test;
-
-{
-    my $flow = Slic3r::Flow->new(
-        width           => 1,
-        height          => 1,
-        nozzle_diameter => 1,
-    );
-    
-    my $config = Slic3r::Config->new;
-    my $test = sub {
-        my ($expolygons, %expected) = @_;
-        
-        my $slices = Slic3r::Surface::Collection->new;
-        $slices->append(Slic3r::Surface->new(
-            surface_type => S_TYPE_INTERNAL,
-            expolygon => $_,
-        )) for @$expolygons;
-        
-        my ($region_config, $object_config, $print_config, $loops, $gap_fill, $fill_surfaces);
-        my $g = Slic3r::Layer::PerimeterGenerator->new(
-            # input:
-            $slices,
-            1,  # layer height
-            $flow,
-            ($region_config = Slic3r::Config::PrintRegion->new),
-            ($object_config = Slic3r::Config::PrintObject->new),
-            ($print_config  = Slic3r::Config::Print->new),
-            
-            # output:
-            ($loops         = Slic3r::ExtrusionPath::Collection->new),
-            ($gap_fill      = Slic3r::ExtrusionPath::Collection->new),
-            ($fill_surfaces = Slic3r::Surface::Collection->new),
-        );
-        $g->config->apply_dynamic($config);
-        $g->process;
-        
-        is scalar(@$loops),
-            scalar(@$expolygons), 'expected number of collections';
-        ok !defined(first { !$_->isa('Slic3r::ExtrusionPath::Collection') } @$loops),
-            'everything is returned as collections';
-        
-        my $flattened_loops = $loops->flatten;
-        my @loops = @$flattened_loops;
-        is scalar(@loops),
-            $expected{total}, 'expected number of loops';
-        is scalar(grep $_->role == EXTR_ROLE_EXTERNAL_PERIMETER, map @$_, @loops),
-            $expected{external}, 'expected number of external loops';
-        is_deeply [ map { ($_->role == EXTR_ROLE_EXTERNAL_PERIMETER) || 0 } map @$_, @loops ],
-            $expected{ext_order}, 'expected external order';
-        is scalar(grep $_->loop_role == EXTRL_ROLE_CONTOUR_INTERNAL_PERIMETER, @loops),
-            $expected{cinternal}, 'expected number of internal contour loops';
-        is scalar(grep $_->polygon->is_counter_clockwise, @loops),
-            $expected{ccw}, 'expected number of ccw loops';
-        is_deeply [ map $_->polygon->is_counter_clockwise, @loops ],
-            $expected{ccw_order}, 'expected ccw/cw order';
-        
-        if ($expected{nesting}) {
-            foreach my $nesting (@{ $expected{nesting} }) {
-                for my $i (1..$#$nesting) {
-                    ok $loops[$nesting->[$i-1]]->polygon->contains_point($loops[$nesting->[$i]]->first_point),
-                        'expected nesting order';
-                }
-            }
-        }
-    };
-    
-    $config->set('perimeters', 3);
-    $test->(
-        [
-            Slic3r::ExPolygon->new(
-                Slic3r::Polygon->new_scale([0,0], [100,0], [100,100], [0,100]),
-            ),
-        ],
-        total       => 3,
-        external    => 1,
-        ext_order   => [0,0,1],
-        cinternal   => 1,
-        ccw         => 3,
-        ccw_order   => [1,1,1],
-        nesting     => [ [2,1,0] ],
-    );
-    $test->(
-        [
-            Slic3r::ExPolygon->new(
-                Slic3r::Polygon->new_scale([0,0], [100,0], [100,100], [0,100]),
-                Slic3r::Polygon->new_scale([40,40], [40,60], [60,60], [60,40]),
-            ),
-        ],
-        total       => 6,
-        external    => 2,
-        ext_order   => [0,0,1,0,0,1],
-        cinternal   => 1,
-        ccw         => 3,
-        ccw_order   => [0,0,0,1,1,1],
-        nesting     => [ [5,4,3,0,1,2] ],
-    );
-    $test->(
-        [
-            Slic3r::ExPolygon->new(
-                Slic3r::Polygon->new_scale([0,0], [200,0], [200,200], [0,200]),
-                Slic3r::Polygon->new_scale([20,20], [20,180], [180,180], [180,20]),
-            ),
-            # nested:
-            Slic3r::ExPolygon->new(
-                Slic3r::Polygon->new_scale([50,50], [150,50], [150,150], [50,150]),
-                Slic3r::Polygon->new_scale([80,80], [80,120], [120,120], [120,80]),
-            ),
-        ],
-        total       => 4*3,
-        external    => 4,
-        ext_order   => [0,0,1,0,0,1,0,0,1,0,0,1],
-        cinternal   => 2,
-        ccw         => 2*3,
-        ccw_order   => [0,0,0,1,1,1,0,0,0,1,1,1],
-    );
-    
-    $config->set('perimeters', 2);
-    $test->(
-        [
-            Slic3r::ExPolygon->new(
-                Slic3r::Polygon->new_scale([0,0], [50,0], [50,50], [0,50]),
-                Slic3r::Polygon->new_scale([7.5,7.5], [7.5,12.5], [12.5,12.5], [12.5,7.5]),
-                Slic3r::Polygon->new_scale([7.5,17.5], [7.5,22.5], [12.5,22.5], [12.5,17.5]),
-                Slic3r::Polygon->new_scale([7.5,27.5], [7.5,32.5], [12.5,32.5], [12.5,27.5]),
-                Slic3r::Polygon->new_scale([7.5,37.5], [7.5,42.5], [12.5,42.5], [12.5,37.5]),
-                Slic3r::Polygon->new_scale([17.5,7.5], [17.5,12.5], [22.5,12.5], [22.5,7.5]),
-            ),
-        ],
-        total       => 12,
-        external    => 6,
-        ext_order   => [0,1,0,1,0,1,0,1,0,1,0,1],
-        cinternal   => 1,
-        ccw         => 2,
-        ccw_order   => [0,0,0,0,0,0,0,0,0,0,1,1],
-        nesting     => [ [0,1],[2,3],[4,5],[6,7],[8,9] ],
-    );
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('skirts', 0);
-    $config->set('fill_density', 0);
-    $config->set('perimeters', 3);
-    $config->set('top_solid_layers', 0);
-    $config->set('bottom_solid_layers', 0);
-    $config->set('cooling', [ 0 ]);                 # to prevent speeds from being altered
-    $config->set('first_layer_speed', '100%');      # to prevent speeds from being altered
-    
-    {
-        my $print = Slic3r::Test::init_print('overhang', config => $config);
-        my $has_cw_loops = 0;
-        my $cur_loop;
-        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-            
-            if ($info->{extruding} && $info->{dist_XY} > 0) {
-                $cur_loop ||= [ [$self->X, $self->Y] ];
-                push @$cur_loop, [ @$info{qw(new_X new_Y)} ];
-            } elsif ($cmd ne 'M73') { # skips remaining time lines (M73)
-                if ($cur_loop) {
-                    $has_cw_loops = 1 if Slic3r::Polygon->new(@$cur_loop)->is_clockwise;
-                    $cur_loop = undef;
-                }
-            }
-        });
-        ok !$has_cw_loops, 'all perimeters extruded ccw';
-    }
-    
-    foreach my $model (qw(cube_with_hole cube_with_concave_hole)) {
-        $config->set('external_perimeter_speed', 68);
-        my $print = Slic3r::Test::init_print(
-            $model,
-            config      => $config,
-            duplicate   => 2,  # we test two copies to make sure ExtrusionLoop objects are not modified in-place (the second object would not detect cw loops and thus would calculate wrong inwards moves)
-        );
-        my $has_cw_loops = my $has_outwards_move = my $starts_on_convex_point = 0;
-        my $cur_loop;
-        my %external_loops = ();  # print_z => count of external loops
-        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-            
-            if ($info->{extruding} && $info->{dist_XY} > 0) {
-                $cur_loop ||= [ [$self->X, $self->Y] ];
-                push @$cur_loop, [ @$info{qw(new_X new_Y)} ];
-            } elsif ($cmd ne 'M73') { # skips remaining time lines (M73)
-                if ($cur_loop) {
-                    $has_cw_loops = 1 if Slic3r::Polygon->new_scale(@$cur_loop)->is_clockwise;
-                    if ($self->F == $config->external_perimeter_speed*60) {
-                        my $move_dest = Slic3r::Point->new_scale(@$info{qw(new_X new_Y)});
-                        
-                        # reset counter for second object
-                        $external_loops{$self->Z} = 0
-                            if defined($external_loops{$self->Z}) && $external_loops{$self->Z} == 2;
-                        
-                        $external_loops{$self->Z}++;
-                        my $is_contour  = $external_loops{$self->Z} == 2;
-                        my $is_hole     = $external_loops{$self->Z} == 1;
-                        
-                        my $loop = Slic3r::Polygon->new_scale(@$cur_loop);
-                        my $loop_contains_point = $loop->contains_point($move_dest);
-                        $has_outwards_move = 1
-                            if (!$loop_contains_point && $is_contour)  # contour should include destination
-                             || ($loop_contains_point && $is_hole);    # hole should not
-                        
-                        if ($model eq 'cube_with_concave_hole') {
-                            # check that loop starts at a concave vertex
-                            my $ccw_angle = $loop->[-2]->ccw($loop->first_point, $loop->[1]);
-                            my $convex = ($ccw_angle > PI);  # whether the angle on the *right* side is convex
-                            $starts_on_convex_point = 1
-                                if ($convex && $is_contour) || (!$convex && $is_hole);
-                        }
-                    }
-                    $cur_loop = undef;
-                }
-            }
-        });
-        ok !$has_cw_loops, 'all perimeters extruded ccw';
-        ok !$has_outwards_move, 'move inwards after completing external loop';
-        ok !$starts_on_convex_point, 'loops start on concave point if any';
-    }
-    
-    {
-        $config->set('perimeters', 1);
-        $config->set('perimeter_speed', 77);
-        $config->set('external_perimeter_speed', 66);
-        $config->set('bridge_speed', 99);
-        $config->set('cooling', [ 1 ]);
-        $config->set('fan_below_layer_time', [ 0 ]);
-        $config->set('slowdown_below_layer_time', [ 0 ]);
-        $config->set('bridge_fan_speed', [ 100 ]);
-        $config->set('bridge_flow_ratio', 33);  # arbitrary value
-        $config->set('overhangs', 1);
-        my $print = Slic3r::Test::init_print('overhang', config => $config);
-        my %layer_speeds = ();  # print Z => [ speeds ]
-        my $fan_speed = 0;
-        my $bridge_mm_per_mm = ($config->nozzle_diameter->[0]**2) / ($config->filament_diameter->[0]**2) * $config->bridge_flow_ratio;
-        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-            
-            $fan_speed = 0 if $cmd eq 'M107';
-            $fan_speed = $args->{S} if $cmd eq 'M106';
-            if ($info->{extruding} && $info->{dist_XY} > 0) {
-                $layer_speeds{$self->Z} ||= {};
-                $layer_speeds{$self->Z}{my $feedrate = $args->{F} // $self->F} = 1;
-                
-                fail 'wrong speed found'
-                    if $feedrate != $config->perimeter_speed*60
-                        && $feedrate != $config->external_perimeter_speed*60
-                        && $feedrate != $config->bridge_speed*60;
-                
-                if ($feedrate == $config->bridge_speed*60) {
-                    fail 'printing overhang but fan is not enabled or running at wrong speed'
-                        if $fan_speed != 255;
-                    my $mm_per_mm = $info->{dist_E} / $info->{dist_XY};
-                    fail 'wrong bridge flow' if abs($mm_per_mm - $bridge_mm_per_mm) > 0.01;
-                } else {
-                    fail 'fan is running when not supposed to'
-                        if $fan_speed > 0;
-                }
-            }
-        });
-        is scalar(grep { keys %$_ > 1 } values %layer_speeds), 1,
-            'only overhang layer has more than one speed';
-    }
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('skirts', 0);
-    $config->set('perimeters', 3);
-    $config->set('layer_height', 0.4);
-    $config->set('first_layer_height', 0.35);
-    $config->set('extra_perimeters', 1);
-    $config->set('cooling', [ 0 ]);                 # to prevent speeds from being altered
-    $config->set('first_layer_speed', '100%');      # to prevent speeds from being altered
-    $config->set('perimeter_speed', 99);
-    $config->set('external_perimeter_speed', 99);
-    $config->set('small_perimeter_speed', 99);
-    $config->set('thin_walls', 0);
-    
-    my $print = Slic3r::Test::init_print('ipadstand', config => $config);
-    my %perimeters = ();  # z => number of loops
-    my $in_loop = 0;
-    Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-        my ($self, $cmd, $args, $info) = @_;
-        
-        if ($info->{extruding} && $info->{dist_XY} > 0 && ($args->{F} // $self->F) == $config->perimeter_speed*60) {
-            $perimeters{$self->Z}++ if !$in_loop;
-            $in_loop = 1;
-        } elsif ($cmd ne 'M73') { # skips remaining time lines (M73)
-            $in_loop = 0;
-        }
-    });
-    ok !(grep { $_ % $config->perimeters } values %perimeters), 'no superfluous extra perimeters';
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('nozzle_diameter', [0.4]);
-    $config->set('perimeters', 2);
-    $config->set('perimeter_extrusion_width', 0.4);
-    $config->set('external_perimeter_extrusion_width', 0.4);
-    $config->set('infill_extrusion_width', 0.53);
-    $config->set('solid_infill_extrusion_width', 0.53);
-    
-    # we just need a pre-filled Print object
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    
-    # override a layer's slices
-    my $expolygon = Slic3r::ExPolygon->new([[-71974463,-139999376],[-71731792,-139987456],[-71706544,-139985616],[-71682119,-139982639],[-71441248,-139946912],[-71417487,-139942895],[-71379384,-139933984],[-71141800,-139874480],[-71105247,-139862895],[-70873544,-139779984],[-70838592,-139765856],[-70614943,-139660064],[-70581783,-139643567],[-70368368,-139515680],[-70323751,-139487872],[-70122160,-139338352],[-70082399,-139306639],[-69894800,-139136624],[-69878679,-139121327],[-69707992,-138933008],[-69668575,-138887343],[-69518775,-138685359],[-69484336,-138631632],[-69356423,-138418207],[-69250040,-138193296],[-69220920,-138128976],[-69137992,-137897168],[-69126095,-137860255],[-69066568,-137622608],[-69057104,-137582511],[-69053079,-137558751],[-69017352,-137317872],[-69014392,-137293456],[-69012543,-137268207],[-68999369,-137000000],[-63999999,-137000000],[-63705947,-136985551],[-63654984,-136977984],[-63414731,-136942351],[-63364756,-136929840],[-63129151,-136870815],[-62851950,-136771631],[-62585807,-136645743],[-62377483,-136520895],[-62333291,-136494415],[-62291908,-136463728],[-62096819,-136319023],[-62058644,-136284432],[-61878676,-136121328],[-61680968,-135903184],[-61650275,-135861807],[-61505591,-135666719],[-61354239,-135414191],[-61332211,-135367615],[-61228359,-135148063],[-61129179,-134870847],[-61057639,-134585262],[-61014451,-134294047],[-61000000,-134000000],[-61000000,-107999999],[-61014451,-107705944],[-61057639,-107414736],[-61129179,-107129152],[-61228359,-106851953],[-61354239,-106585808],[-61505591,-106333288],[-61680967,-106096816],[-61878675,-105878680],[-62096820,-105680967],[-62138204,-105650279],[-62333292,-105505591],[-62585808,-105354239],[-62632384,-105332207],[-62851951,-105228360],[-62900463,-105211008],[-63129152,-105129183],[-63414731,-105057640],[-63705947,-105014448],[-63999999,-105000000],[-68999369,-105000000],[-69012543,-104731792],[-69014392,-104706544],[-69017352,-104682119],[-69053079,-104441248],[-69057104,-104417487],[-69066008,-104379383],[-69125528,-104141799],[-69137111,-104105248],[-69220007,-103873544],[-69234136,-103838591],[-69339920,-103614943],[-69356415,-103581784],[-69484328,-103368367],[-69512143,-103323752],[-69661647,-103122160],[-69693352,-103082399],[-69863383,-102894800],[-69878680,-102878679],[-70066999,-102707992],[-70112656,-102668576],[-70314648,-102518775],[-70368367,-102484336],[-70581783,-102356424],[-70806711,-102250040],[-70871040,-102220919],[-71102823,-102137992],[-71139752,-102126095],[-71377383,-102066568],[-71417487,-102057104],[-71441248,-102053079],[-71682119,-102017352],[-71706535,-102014392],[-71731784,-102012543],[-71974456,-102000624],[-71999999,-102000000],[-104000000,-102000000],[-104025536,-102000624],[-104268207,-102012543],[-104293455,-102014392],[-104317880,-102017352],[-104558751,-102053079],[-104582512,-102057104],[-104620616,-102066008],[-104858200,-102125528],[-104894751,-102137111],[-105126455,-102220007],[-105161408,-102234136],[-105385056,-102339920],[-105418215,-102356415],[-105631632,-102484328],[-105676247,-102512143],[-105877839,-102661647],[-105917600,-102693352],[-106105199,-102863383],[-106121320,-102878680],[-106292007,-103066999],[-106331424,-103112656],[-106481224,-103314648],[-106515663,-103368367],[-106643575,-103581783],[-106749959,-103806711],[-106779080,-103871040],[-106862007,-104102823],[-106873904,-104139752],[-106933431,-104377383],[-106942896,-104417487],[-106946920,-104441248],[-106982648,-104682119],[-106985607,-104706535],[-106987456,-104731784],[-107000630,-105000000],[-112000000,-105000000],[-112294056,-105014448],[-112585264,-105057640],[-112870848,-105129184],[-112919359,-105146535],[-113148048,-105228360],[-113194624,-105250392],[-113414191,-105354239],[-113666711,-105505591],[-113708095,-105536279],[-113903183,-105680967],[-114121320,-105878679],[-114319032,-106096816],[-114349720,-106138200],[-114494408,-106333288],[-114645760,-106585808],[-114667792,-106632384],[-114771640,-106851952],[-114788991,-106900463],[-114870815,-107129151],[-114942359,-107414735],[-114985551,-107705943],[-115000000,-107999999],[-115000000,-134000000],[-114985551,-134294048],[-114942359,-134585263],[-114870816,-134870847],[-114853464,-134919359],[-114771639,-135148064],[-114645759,-135414192],[-114494407,-135666720],[-114319031,-135903184],[-114121320,-136121327],[-114083144,-136155919],[-113903184,-136319023],[-113861799,-136349712],[-113666711,-136494416],[-113458383,-136619264],[-113414192,-136645743],[-113148049,-136771631],[-112870848,-136870815],[-112820872,-136883327],[-112585264,-136942351],[-112534303,-136949920],[-112294056,-136985551],[-112000000,-137000000],[-107000630,-137000000],[-106987456,-137268207],[-106985608,-137293440],[-106982647,-137317872],[-106946920,-137558751],[-106942896,-137582511],[-106933991,-137620624],[-106874471,-137858208],[-106862888,-137894751],[-106779992,-138126463],[-106765863,-138161424],[-106660080,-138385055],[-106643584,-138418223],[-106515671,-138631648],[-106487855,-138676256],[-106338352,-138877839],[-106306647,-138917600],[-106136616,-139105199],[-106121320,-139121328],[-105933000,-139291999],[-105887344,-139331407],[-105685351,-139481232],[-105631632,-139515663],[-105418216,-139643567],[-105193288,-139749951],[-105128959,-139779072],[-104897175,-139862016],[-104860247,-139873904],[-104622616,-139933423],[-104582511,-139942896],[-104558751,-139946912],[-104317880,-139982656],[-104293463,-139985616],[-104268216,-139987456],[-104025544,-139999376],[-104000000,-140000000],[-71999999,-140000000]],[[-105000000,-138000000],[-105000000,-104000000],[-71000000,-104000000],[-71000000,-138000000]],[[-69000000,-132000000],[-69000000,-110000000],[-64991180,-110000000],[-64991180,-132000000]],[[-111008824,-132000000],[-111008824,-110000000],[-107000000,-110000000],[-107000000,-132000000]]);
-    my $object = $print->print->objects->[0];
-    $object->slice;
-    my $layer = $object->get_layer(1);
-    my $layerm = $layer->regions->[0];
-    $layerm->slices->clear;
-    $layerm->slices->append(Slic3r::Surface->new(surface_type => S_TYPE_INTERNAL, expolygon => $expolygon));
-    
-    # make perimeters
-    $layer->make_perimeters;
-    
-    # compute the covered area
-    my $pflow = $layerm->flow(FLOW_ROLE_PERIMETER);
-    my $iflow = $layerm->flow(FLOW_ROLE_INFILL);
-    my $covered_by_perimeters = union_ex([
-        (map @{$_->polygon->split_at_first_point->grow($pflow->scaled_width/2)}, map @$_, @{$layerm->perimeters}),
-    ]);
-    my $covered_by_infill = union_ex([
-        (map $_->p, @{$layerm->fill_surfaces}),
-        (map @{$_->polyline->grow($iflow->scaled_width/2)}, @{$layerm->thin_fills}),
-    ]);
-    
-    # compute the non covered area
-    my $non_covered = diff(
-        [ map @{$_->expolygon}, @{$layerm->slices} ],
-        [ map @$_, (@$covered_by_perimeters, @$covered_by_infill) ],
-    );
-    
-    if (0) {
-        printf "max non covered = %f\n", List::Util::max(map unscale unscale $_->area, @$non_covered);
-        require "Slic3r/SVG.pm";
-        Slic3r::SVG::output(
-            "gaps.svg",
-            expolygons          => [ map $_->expolygon, @{$layerm->slices} ],
-            red_expolygons      => union_ex([ map @$_, (@$covered_by_perimeters, @$covered_by_infill) ]),
-            green_expolygons    => union_ex($non_covered),
-            no_arrows           => 1,
-            polylines           => [
-                map $_->polygon->split_at_first_point, map @$_, @{$layerm->perimeters},
-            ],
-        );
-    }
-    ok !(defined first { $_->area > ($iflow->scaled_width**2) } @$non_covered), 'no gap between perimeters and infill';
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('skirts', 0);
-    $config->set('perimeters', 3);
-    $config->set('layer_height', 0.4);
-    $config->set('bridge_speed', 99);
-    $config->set('fill_density', 0);                # to prevent bridging over sparse infill
-    $config->set('overhangs', 1);
-    $config->set('cooling', [ 0 ]);                 # to prevent speeds from being altered
-    $config->set('first_layer_speed', '100%');      # to prevent speeds from being altered
-    
-    my $test = sub {
-        my ($print) = @_;
-        my %z_with_bridges = ();  # z => 1
-        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-        
-            if ($info->{extruding} && $info->{dist_XY} > 0) {
-                $z_with_bridges{$self->Z} = 1 if ($args->{F} // $self->F) == $config->bridge_speed*60;
-            }
-        });
-        return scalar keys %z_with_bridges;
-    };
-    ok $test->(Slic3r::Test::init_print('V', config => $config)) == 1,
-        'no overhangs printed with bridge speed';  # except for the two internal solid layers above void
-    ok $test->(Slic3r::Test::init_print('V', config => $config, scale_xyz => [3,1,1])) > 2,
-        'overhangs printed with bridge speed';
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('seam_position', 'random');
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    ok Slic3r::Test::gcode($print), 'successful generation of G-code with seam_position = random';
-}
-
-{
-    my $test = sub {
-        my ($model_name) = @_;
-        my $config = Slic3r::Config::new_from_defaults;
-        $config->set('seam_position', 'aligned');
-        $config->set('skirts', 0);
-        $config->set('perimeters', 1);
-        $config->set('fill_density', 0);
-        $config->set('top_solid_layers', 0);
-        $config->set('bottom_solid_layers', 0);
-        $config->set('retract_layer_change', [0]);
-    
-        my $was_extruding = 0;
-        my @seam_points = ();
-        my $print = Slic3r::Test::init_print($model_name, config => $config);
-        Slic3r::GCode::Reader->new->parse(my $gcode = Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-    
-            if ($info->{extruding}) {
-                if (!$was_extruding) {
-                    push @seam_points, Slic3r::Point->new_scale($self->X, $self->Y);
-                }
-                $was_extruding = 1;
-            } elsif ($cmd ne 'M73') { # skips remaining time lines (M73)
-                $was_extruding = 0;
-            }
-        });
-        my @dist = map unscale($_), map $seam_points[$_]->distance_to($seam_points[$_+1]), 0..($#seam_points-1);
-        ok !(defined first { $_ > 3 } @dist), 'seam is aligned';
-    };
-    $test->('20mm_cube');
-    $test->('small_dorito');
-}
-
-__END__
diff --git a/t/slice.t b/t/slice.t
deleted file mode 100644
index 2f193aae3..000000000
--- a/t/slice.t
+++ /dev/null
@@ -1,152 +0,0 @@
-use Test::More;
-use strict;
-use warnings;
-
-plan skip_all => 'temporarily disabled';
-plan tests => 16;
-
-BEGIN {
-    use FindBin;
-    use lib "$FindBin::Bin/../lib";
-    use local::lib "$FindBin::Bin/../local-lib";
-}
-
-# temporarily disable compilation errors due to constant not being exported anymore
-sub Slic3r::TriangleMesh::I_B {}
-sub Slic3r::TriangleMesh::I_FACET_EDGE {}
-sub Slic3r::TriangleMesh::FE_BOTTOM {
-sub Slic3r::TriangleMesh::FE_TOP {}}
-
-use Slic3r;
-use Slic3r::Geometry qw(X Y Z);
-
-my @lines;
-my $z = 20;
-my @points = ([3, 4], [8, 5], [1, 9]);  # XY coordinates of the facet vertices
-
-# NOTE:
-# the first point of the intersection lines is replaced by -1 because TriangleMesh.pm
-# is saving memory and doesn't store point A anymore since it's not actually needed.
-
-# We disable this test because intersect_facet() now assumes we never feed a horizontal
-# facet to it.
-# is_deeply lines(20, 20, 20), [
-#     [ -1, $points[1] ],  # $points[0]
-#     [ -1, $points[2] ],  # $points[1]
-#     [ -1, $points[0] ],  # $points[2]
-# ], 'horizontal';
-
-is_deeply lines(22, 20, 20), [ [ -1, $points[2] ] ], 'lower edge on layer';  # $points[1]
-is_deeply lines(20, 20, 22), [ [ -1, $points[1] ] ], 'lower edge on layer';  # $points[0]
-is_deeply lines(20, 22, 20), [ [ -1, $points[0] ] ], 'lower edge on layer';  # $points[2]
-
-is_deeply lines(20, 20, 10), [ [ -1, $points[0] ] ], 'upper edge on layer';  # $points[1]
-is_deeply lines(10, 20, 20), [ [ -1, $points[1] ] ], 'upper edge on layer';  # $points[2]
-is_deeply lines(20, 10, 20), [ [ -1, $points[2] ] ], 'upper edge on layer';  # $points[0]
-
-is_deeply lines(20, 15, 10), [                            ], 'upper vertex on layer';
-is_deeply lines(28, 20, 30), [                            ], 'lower vertex on layer';
-
-{
-    my @z = (24, 10, 16);
-    is_deeply lines(@z), [
-        [
-            -1, # line_plane_intersection([ vertices(@z)->[0], vertices(@z)->[1] ]),
-            line_plane_intersection([ vertices(@z)->[2], vertices(@z)->[0] ]),
-        ]
-    ], 'two edges intersect';
-}
-
-{
-    my @z = (16, 24, 10);
-    is_deeply lines(@z), [
-        [
-            -1, # line_plane_intersection([ vertices(@z)->[1], vertices(@z)->[2] ]),
-            line_plane_intersection([ vertices(@z)->[0], vertices(@z)->[1] ]),
-        ]
-    ], 'two edges intersect';
-}
-
-{
-    my @z = (10, 16, 24);
-    is_deeply lines(@z), [
-        [
-            -1, # line_plane_intersection([ vertices(@z)->[2], vertices(@z)->[0] ]),
-            line_plane_intersection([ vertices(@z)->[1], vertices(@z)->[2] ]),
-        ]
-    ], 'two edges intersect';
-}
-
-{
-    my @z = (24, 10, 20);
-    is_deeply lines(@z), [
-        [
-            -1, # line_plane_intersection([ vertices(@z)->[0], vertices(@z)->[1] ]),
-            $points[2],
-        ]
-    ], 'one vertex on plane and one edge intersects';
-}
-
-{
-    my @z = (10, 20, 24);
-    is_deeply lines(@z), [
-        [
-            -1, # line_plane_intersection([ vertices(@z)->[2], vertices(@z)->[0] ]),
-            $points[1],
-        ]
-    ], 'one vertex on plane and one edge intersects';
-}
-
-{
-    my @z = (20, 24, 10);
-    is_deeply lines(@z), [
-        [
-            -1, # line_plane_intersection([ vertices(@z)->[1], vertices(@z)->[2] ]),
-            $points[0],
-        ]
-    ], 'one vertex on plane and one edge intersects';
-}
-
-my @lower = intersect(22, 20, 20);
-my @upper = intersect(20, 20, 10);
-is $lower[0][Slic3r::TriangleMesh::I_FACET_EDGE], Slic3r::TriangleMesh::FE_BOTTOM, 'bottom edge on layer';
-is $upper[0][Slic3r::TriangleMesh::I_FACET_EDGE], Slic3r::TriangleMesh::FE_TOP, 'upper edge on layer';
-
-my $mesh;
-
-sub intersect {
-    $mesh = Slic3r::TriangleMesh->new(
-        facets      => [],
-        vertices    => [],
-    );
-    push @{$mesh->facets}, [ [0,0,0], @{vertices(@_)} ];
-    $mesh->analyze;
-    return map Slic3r::TriangleMesh::unpack_line($_), $mesh->intersect_facet($#{$mesh->facets}, $z);
-}
-
-sub vertices {
-    push @{$mesh->vertices}, map [ @{$points[$_]}, $_[$_] ], 0..2;
-    [ ($#{$mesh->vertices}-2) .. $#{$mesh->vertices} ]
-}
-
-sub lines {
-    my @lines = intersect(@_);
-    #$_->a->[X] = sprintf('%.0f', $_->a->[X]) for @lines;
-    #$_->a->[Y] = sprintf('%.0f', $_->a->[Y]) for @lines;
-    $_->[Slic3r::TriangleMesh::I_B][X] = sprintf('%.0f', $_->[Slic3r::TriangleMesh::I_B][X]) for @lines;
-    $_->[Slic3r::TriangleMesh::I_B][Y] = sprintf('%.0f', $_->[Slic3r::TriangleMesh::I_B][Y]) for @lines;
-    return [ map [ -1, $_->[Slic3r::TriangleMesh::I_B] ], @lines ];
-}
-
-sub line_plane_intersection {
-    my ($line) = @_;
-    @$line = map $mesh->vertices->[$_], @$line;
-    
-    return [
-        map sprintf('%.0f', $_),
-            map +($line->[1][$_] + ($line->[0][$_] - $line->[1][$_]) * ($z - $line->[1][Z]) / ($line->[0][Z] - $line->[1][Z])),
-                (X,Y)
-    ];
-}
-
-__END__
diff --git a/t/support.t b/t/support.t
deleted file mode 100644
index 0283df22b..000000000
--- a/t/support.t
+++ /dev/null
@@ -1,272 +0,0 @@
-use Test::More;
-use strict;
-use warnings;
-
-plan skip_all => 'temporarily disabled';
-plan tests => 27;
-
-BEGIN {
-    use FindBin;
-    use lib "$FindBin::Bin/../lib";
-    use local::lib "$FindBin::Bin/../local-lib";
-}
-
-use List::Util qw(first);
-use Slic3r;
-use Slic3r::Flow ':roles';
-use Slic3r::Geometry qw(epsilon scale);
-use Slic3r::Geometry::Clipper qw(diff);
-use Slic3r::Test;
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('support_material', 1);
-    my @contact_z = my @top_z = ();
-    
-    my $test = sub {
-        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-        my $object_config = $print->print->objects->[0]->config;
-        my $flow = Slic3r::Flow->new_from_width(
-            width               => $object_config->support_material_extrusion_width || $object_config->extrusion_width,
-            role                => FLOW_ROLE_SUPPORT_MATERIAL,
-            nozzle_diameter     => $print->config->nozzle_diameter->[$object_config->support_material_extruder-1] // $print->config->nozzle_diameter->[0],
-            layer_height        => $object_config->layer_height,
-        );
-        my $support = Slic3r::Print::SupportMaterial->new(
-            object_config       => $print->print->objects->[0]->config,
-            print_config        => $print->print->config,
-            flow                => $flow,
-            interface_flow      => $flow,
-            first_layer_flow    => $flow,
-        );
-        my $support_z = $support->support_layers_z($print->print->objects->[0], \@contact_z, \@top_z, $config->layer_height);
-        my $expected_top_spacing = $support->contact_distance($config->layer_height, $config->nozzle_diameter->[0]);
-        
-        is $support_z->[0], $config->first_layer_height,
-            'first layer height is honored';
-        is scalar(grep { $support_z->[$_]-$support_z->[$_-1] <= 0 } 1..$#$support_z), 0,
-            'no null or negative support layers';
-        is scalar(grep { $support_z->[$_]-$support_z->[$_-1] > $config->nozzle_diameter->[0] + epsilon } 1..$#$support_z), 0,
-            'no layers thicker than nozzle diameter';
-        
-        my $wrong_top_spacing = 0;
-        foreach my $top_z (@top_z) {
-            # find layer index of this top surface
-            my $layer_id = first { abs($support_z->[$_] - $top_z) < epsilon } 0..$#$support_z;
-            
-            # check that first support layer above this top surface (or the next one) is spaced with nozzle diameter
-            $wrong_top_spacing = 1
-                if ($support_z->[$layer_id+1] - $support_z->[$layer_id]) != $expected_top_spacing
-                && ($support_z->[$layer_id+2] - $support_z->[$layer_id]) != $expected_top_spacing;
-        }
-        ok !$wrong_top_spacing, 'layers above top surfaces are spaced correctly';
-    };
-    
-    $config->set('layer_height', 0.2);
-    $config->set('first_layer_height', 0.3);
-    @contact_z = (1.9);
-    @top_z = (1.1);
-    $test->();
-    
-    $config->set('first_layer_height', 0.4);
-    $test->();
-    
-    $config->set('layer_height', $config->nozzle_diameter->[0]);
-    $test->();
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('raft_layers', 3);
-    $config->set('brim_width',  0);
-    $config->set('skirts', 0);
-    $config->set('support_material_extruder', 2);
-    $config->set('support_material_interface_extruder', 2);
-    $config->set('layer_height', 0.4);
-    $config->set('first_layer_height', 0.4);
-    my $print = Slic3r::Test::init_print('overhang', config => $config);
-    ok my $gcode = Slic3r::Test::gcode($print), 'no conflict between raft/support and brim';
-    
-    my $tool = 0;
-    Slic3r::GCode::Reader->new->parse($gcode, sub {
-        my ($self, $cmd, $args, $info) = @_;
-        
-        if ($cmd =~ /^T(\d+)/) {
-            $tool = $1;
-        } elsif ($info->{extruding}) {
-            if ($self->Z <= ($config->raft_layers * $config->layer_height)) {
-                fail 'not extruding raft with support material extruder'
-                    if $tool != ($config->support_material_extruder-1);
-            } else {
-                fail 'support material exceeds raft layers'
-                    if $tool == $config->support_material_extruder-1;
-                # TODO: we should test that full support is generated when we use raft too
-            }
-        }
-    });
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('skirts', 0);
-    $config->set('raft_layers', 3);
-    $config->set('support_material_pattern', 'honeycomb');
-    $config->set('support_material_extrusion_width', 0.6);
-    $config->set('first_layer_extrusion_width', '100%');
-    $config->set('bridge_speed', 99);
-    $config->set('cooling', [ 0 ]);             # prevent speed alteration
-    $config->set('first_layer_speed', '100%');  # prevent speed alteration
-    $config->set('start_gcode', '');            # prevent any unexpected Z move
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    
-    my $layer_id = -1;  # so that first Z move sets this to 0
-    my @raft = my @first_object_layer = ();
-    my %first_object_layer_speeds = ();  # F => 1
-    Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-        my ($self, $cmd, $args, $info) = @_;
-        
-        if ($info->{extruding} && $info->{dist_XY} > 0) {
-            if ($layer_id <= $config->raft_layers) {
-                # this is a raft layer or the first object layer
-                my $line = Slic3r::Line->new_scale([ $self->X, $self->Y ], [ $info->{new_X}, $info->{new_Y} ]);
-                my @path = @{$line->grow(scale($config->support_material_extrusion_width/2))};
-                if ($layer_id < $config->raft_layers) {
-                    # this is a raft layer
-                    push @raft, @path;
-                } else {
-                    push @first_object_layer, @path;
-                    $first_object_layer_speeds{ $args->{F} // $self->F } = 1;
-                }
-            }
-        } elsif ($cmd eq 'G1' && $info->{dist_Z} > 0) {
-            $layer_id++;
-        }
-    });
-    
-    ok !@{diff(\@first_object_layer, \@raft)},
-        'first object layer is completely supported by raft';
-    is scalar(keys %first_object_layer_speeds), 1,
-        'only one speed used in first object layer';
-    ok +(keys %first_object_layer_speeds)[0] == $config->bridge_speed*60,
-        'bridge speed used in first object layer';
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('skirts', 0);
-    $config->set('layer_height', 0.35);
-    $config->set('first_layer_height', 0.3);
-    $config->set('nozzle_diameter', [0.5]);
-    $config->set('support_material_extruder', 2);
-    $config->set('support_material_interface_extruder', 2);
-    
-    my $test = sub {
-        my ($raft_layers) = @_;
-        $config->set('raft_layers', $raft_layers);
-        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-        my %raft_z = ();  # z => 1
-        my $tool = undef;
-        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-        
-            if ($cmd =~ /^T(\d+)/) {
-                $tool = $1;
-            } elsif ($info->{extruding} && $info->{dist_XY} > 0) {
-                if ($tool == $config->support_material_extruder-1) {
-                    $raft_z{$self->Z} = 1;
-                }
-            }
-        });
-    
-        is scalar(keys %raft_z), $config->raft_layers, 'correct number of raft layers is generated';
-    };
-    
-    $test->(2);
-    $test->(70);
-    
-    $config->set('layer_height', 0.4);
-    $config->set('first_layer_height', 0.35);
-    $test->(3);
-    $test->(70);
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('brim_width',  0);
-    $config->set('skirts', 0);
-    $config->set('support_material', 1);
-    $config->set('top_solid_layers', 0); # so that we don't have the internal bridge over infill
-    $config->set('bridge_speed', 99);
-    $config->set('cooling', [ 0 ]);
-    $config->set('first_layer_speed', '100%');
-    
-    my $test = sub {
-        my $print = Slic3r::Test::init_print('overhang', config => $config);
-    
-        my $has_bridge_speed = 0;
-        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-            my ($self, $cmd, $args, $info) = @_;
-        
-            if ($info->{extruding}) {
-                if (($args->{F} // $self->F) == $config->bridge_speed*60) {
-                    $has_bridge_speed = 1;
-                }
-            }
-        });
-        return $has_bridge_speed;
-    };
-    
-    $config->set('support_material_contact_distance', 0.2);
-    ok $test->(), 'bridge speed is used when support_material_contact_distance > 0';
-    
-    $config->set('support_material_contact_distance', 0);
-    ok !$test->(), 'bridge speed is not used when support_material_contact_distance == 0';
-    
-    $config->set('raft_layers', 5);
-    $config->set('support_material_contact_distance', 0.2);
-    ok $test->(), 'bridge speed is used when raft_layers > 0 and support_material_contact_distance > 0';
-    
-    $config->set('support_material_contact_distance', 0);
-    ok !$test->(), 'bridge speed is not used when raft_layers > 0 and support_material_contact_distance == 0';
-}
-
-{
-    my $config = Slic3r::Config::new_from_defaults;
-    $config->set('skirts', 0);
-    $config->set('start_gcode', '');
-    $config->set('raft_layers', 8);
-    $config->set('nozzle_diameter', [0.4, 1]);
-    $config->set('layer_height', 0.1);
-    $config->set('first_layer_height', 0.8);
-    $config->set('support_material_extruder', 2);
-    $config->set('support_material_interface_extruder', 2);
-    $config->set('support_material_contact_distance', 0);
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    ok my $gcode = Slic3r::Test::gcode($print), 'first_layer_height is validated with support material extruder nozzle diameter when using raft layers';
-    
-    my $tool = undef;
-    my @z = (0);
-    my %layer_heights_by_tool = ();  # tool => [ lh, lh... ]
-    Slic3r::GCode::Reader->new->parse($gcode, sub {
-        my ($self, $cmd, $args, $info) = @_;
-    
-        if ($cmd =~ /^T(\d+)/) {
-            $tool = $1;
-        } elsif ($cmd eq 'G1' && exists $args->{Z} && $args->{Z} != $self->Z) {
-            push @z, $args->{Z};
-        } elsif ($info->{extruding} && $info->{dist_XY} > 0) {
-            $layer_heights_by_tool{$tool} ||= [];
-            push @{ $layer_heights_by_tool{$tool} }, $z[-1] - $z[-2];
-        }
-    });
-    
-    ok !defined(first { $_ > $config->nozzle_diameter->[0] + epsilon }
-        @{ $layer_heights_by_tool{$config->perimeter_extruder-1} }),
-        'no object layer is thicker than nozzle diameter';
-    
-    ok !defined(first { abs($_ - $config->layer_height) < epsilon }
-        @{ $layer_heights_by_tool{$config->support_material_extruder-1} }),
-        'no support material layer is as thin as object layers';
-}
-
-__END__
diff --git a/tests/fff_print/CMakeLists.txt b/tests/fff_print/CMakeLists.txt
index 50b45e384..28f75bf2c 100644
--- a/tests/fff_print/CMakeLists.txt
+++ b/tests/fff_print/CMakeLists.txt
@@ -10,6 +10,8 @@ add_executable(${_TEST_NAME}_tests
 	test_gcodefindreplace.cpp
 	test_gcodewriter.cpp
 	test_model.cpp
+	test_multi.cpp
+	test_perimeters.cpp
 	test_print.cpp
 	test_printgcode.cpp
 	test_printobject.cpp
diff --git a/tests/fff_print/test_extrusion_entity.cpp b/tests/fff_print/test_extrusion_entity.cpp
index 7e0ca822f..c98e0ec1a 100644
--- a/tests/fff_print/test_extrusion_entity.cpp
+++ b/tests/fff_print/test_extrusion_entity.cpp
@@ -140,4 +140,11 @@ TEST_CASE("ExtrusionEntityCollection: Chained path", "[ExtrusionEntity]") {
             REQUIRE(p1 == p2);
         }
     }
-}
\ No newline at end of file
+}
+
+TEST_CASE("ExtrusionEntityCollection: Chained path with no explicit starting point", "[ExtrusionEntity]") {
+    auto polylines = Polylines { { { 0, 15 }, {0, 18}, {0, 20} }, { { 0, 10 }, {0, 8}, {0, 5} } };
+    auto target    = Polylines { { {0, 5}, {0, 8}, { 0, 10 } }, { { 0, 15 }, {0, 18}, {0, 20} } };
+    auto chained   = chain_polylines(polylines);
+    REQUIRE(chained == target);
+}
diff --git a/tests/fff_print/test_multi.cpp b/tests/fff_print/test_multi.cpp
new file mode 100644
index 000000000..03c7f644b
--- /dev/null
+++ b/tests/fff_print/test_multi.cpp
@@ -0,0 +1,268 @@
+#include <catch2/catch.hpp>
+
+#include <numeric>
+#include <sstream>
+
+#include "libslic3r/ClipperUtils.hpp"
+#include "libslic3r/Geometry.hpp"
+#include "libslic3r/Geometry/ConvexHull.hpp"
+#include "libslic3r/Print.hpp"
+#include "libslic3r/libslic3r.h"
+
+#include "test_data.hpp"
+
+using namespace Slic3r;
+using namespace std::literals;
+
+SCENARIO("Basic tests", "[Multi]")
+{
+    WHEN("Slicing multi-material print with non-consecutive extruders") {
+        std::string gcode = Slic3r::Test::slice({ Slic3r::Test::TestMesh::cube_20x20x20 }, 
+            {
+                { "nozzle_diameter",                "0.6, 0.6, 0.6, 0.6" },
+                { "extruder",                       2 },
+                { "infill_extruder",                4 },
+                { "support_material_extruder",      0 }
+            });
+        THEN("Sliced successfully") {
+            REQUIRE(! gcode.empty());
+        }
+        THEN("T3 toolchange command found") {
+            bool T1_found = gcode.find("\nT3\n") != gcode.npos;
+            REQUIRE(T1_found);
+        }
+    }
+    WHEN("Slicing with multiple skirts with a single, non-zero extruder") {
+        std::string gcode = Slic3r::Test::slice({ Slic3r::Test::TestMesh::cube_20x20x20 }, 
+            {
+                { "nozzle_diameter",                        "0.6, 0.6, 0.6, 0.6" },
+                { "perimeter_extruder",                     2 },
+                { "infill_extruder",                        2 },
+                { "support_material_extruder",              2 },
+                { "support_material_interface_extruder",    2 },
+            });
+        THEN("Sliced successfully") {
+            REQUIRE(! gcode.empty());
+        }
+    }
+}
+
+SCENARIO("Ooze prevention", "[Multi]")
+{
+    DynamicPrintConfig config = Slic3r::DynamicPrintConfig::full_print_config_with({
+        { "nozzle_diameter",                "0.6, 0.6, 0.6, 0.6" },
+        { "raft_layers",                    2 },
+        { "infill_extruder",                2 },
+        { "solid_infill_extruder",          3 },
+        { "support_material_extruder",      4 },
+        { "ooze_prevention",                1 },
+        { "extruder_offset",                "0x0, 20x0, 0x20, 20x20" },
+        { "temperature",                    "200, 180, 170, 160" },
+        { "first_layer_temperature",        "206, 186, 166, 156" },
+        // test that it doesn't crash when this is supplied
+        { "toolchange_gcode",               "T[next_extruder] ;toolchange" }
+    });
+    FullPrintConfig print_config;
+    print_config.apply(config);
+
+    // Since July 2019, PrusaSlicer only emits automatic Tn command in case that the toolchange_gcode is empty
+    // The "T[next_extruder]" is therefore needed in this test.
+    
+    std::string gcode = Slic3r::Test::slice({ Slic3r::Test::TestMesh::cube_20x20x20 }, config);
+
+    GCodeReader parser;
+    int         tool = -1;
+    int         tool_temp[] = { 0, 0, 0, 0};
+    Points      toolchange_points;
+    Points      extrusion_points;
+    parser.parse_buffer(gcode, [&tool, &tool_temp, &toolchange_points, &extrusion_points, &print_config]
+        (Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+    {
+        // if the command is a T command, set the the current tool
+        if (boost::starts_with(line.cmd(), "T")) {
+            // Ignore initial toolchange.
+            if (tool != -1) {
+                int expected_temp = is_approx<double>(self.z(), print_config.get_abs_value("first_layer_height") + print_config.z_offset) ?
+                    print_config.first_layer_temperature.get_at(tool) :
+                    print_config.temperature.get_at(tool);
+                if (tool_temp[tool] != expected_temp + print_config.standby_temperature_delta)
+                    throw std::runtime_error("Standby temperature was not set before toolchange.");
+                toolchange_points.emplace_back(self.xy_scaled());
+            }
+            tool = atoi(line.cmd().data() + 1);
+        } else if (line.cmd_is("M104") || line.cmd_is("M109")) {
+            // May not be defined on this line.
+            int t = tool;
+            line.has_value('T', t);
+            // Should be available on this line.
+            int s;
+            if (! line.has_value('S', s))
+                throw std::runtime_error("M104 or M109 without S");
+            if (tool_temp[t] == 0 && s != print_config.first_layer_temperature.get_at(t) + print_config.standby_temperature_delta)
+                throw std::runtime_error("initial temperature is not equal to first layer temperature + standby delta");
+            tool_temp[t] = s;
+        } else if (line.cmd_is("G1") && line.extruding(self) && line.dist_XY(self) > 0) {
+            extrusion_points.emplace_back(line.new_XY_scaled(self) + scaled<coord_t>(print_config.extruder_offset.get_at(tool)));
+        }
+    });
+
+    Polygon convex_hull = Geometry::convex_hull(extrusion_points);
+    
+    THEN("all nozzles are outside skirt at toolchange") {
+        Points t;
+        sort_remove_duplicates(toolchange_points);
+        size_t inside = 0;
+        for (const auto &point : toolchange_points)
+            for (const Vec2d &offset : print_config.extruder_offset.values) {
+                Point p = point + scaled<coord_t>(offset);
+                if (convex_hull.contains(p))
+                    ++ inside;
+            }
+        REQUIRE(inside == 0);
+    }
+
+#if 0
+    require "Slic3r/SVG.pm";
+    Slic3r::SVG::output(
+        "ooze_prevention_test.svg",
+        no_arrows   => 1,
+        polygons    => [$convex_hull],
+        red_points  => \@t,
+        points      => \@toolchange_points,
+    );
+#endif
+    
+    THEN("all toolchanges happen within expected area") {
+        // offset the skirt by the maximum displacement between extruders plus a safety extra margin
+        const float delta = scaled<float>(20. * sqrt(2.) + 1.);
+        Polygon outer_convex_hull = expand(convex_hull, delta).front();
+        size_t inside = std::count_if(toolchange_points.begin(), toolchange_points.end(), [&outer_convex_hull](const Point &p){ return outer_convex_hull.contains(p); });
+        REQUIRE(inside == toolchange_points.size());
+    }
+}
+
+std::string slice_stacked_cubes(const DynamicPrintConfig &config, const DynamicPrintConfig &volume1config, const DynamicPrintConfig &volume2config)
+{
+    Model        model;
+    ModelObject *object = model.add_object();
+    object->name = "object.stl";
+    ModelVolume *v1 = object->add_volume(Test::mesh(Test::TestMesh::cube_20x20x20));
+    v1->set_material_id("lower_material");
+    v1->config.assign_config(volume1config);
+    ModelVolume *v2 = object->add_volume(Test::mesh(Test::TestMesh::cube_20x20x20));
+    v2->set_material_id("upper_material");
+    v2->translate(0., 0., 20.);
+    v2->config.assign_config(volume2config);
+    object->add_instance();
+    object->ensure_on_bed();
+    Print print;
+    print.auto_assign_extruders(object);
+    THEN("auto_assign_extruders() assigned correct extruder to first volume") {
+        REQUIRE(v1->config.extruder() == 1);
+    }
+    THEN("auto_assign_extruders() assigned correct extruder to second volume") {
+        REQUIRE(v2->config.extruder() == 2);
+    }
+    print.apply(model, config);
+    print.validate();
+    return Test::gcode(print);
+}
+
+SCENARIO("Stacked cubes", "[Multi]")
+{
+    DynamicPrintConfig lower_config;
+    lower_config.set_deserialize_strict({
+        { "extruder",               1 },
+        { "bottom_solid_layers",    0 },
+        { "top_solid_layers",       1 },
+    });
+
+    DynamicPrintConfig upper_config;
+    upper_config.set_deserialize_strict({
+        { "extruder",               2 },
+        { "bottom_solid_layers",    1 },
+        { "top_solid_layers",       0 }
+    });
+
+    static constexpr const double solid_infill_speed = 99;
+    auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+        { "nozzle_diameter",        "0.6, 0.6, 0.6, 0.6" },
+        { "fill_density",           0 },
+        { "solid_infill_speed",     solid_infill_speed },
+        { "top_solid_infill_speed", solid_infill_speed },
+        // for preventing speeds from being altered
+        { "cooling",                "0, 0, 0, 0" },
+        // for preventing speeds from being altered
+        { "first_layer_speed",      "100%" }
+    });
+
+    auto test_shells = [](const std::string &gcode) {
+        GCodeReader       parser;
+        int               tool = -1;
+        // Scaled Z heights.
+        std::set<coord_t> T0_shells, T1_shells;
+        parser.parse_buffer(gcode, [&tool, &T0_shells, &T1_shells]
+            (Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+        {
+            if (boost::starts_with(line.cmd(), "T")) {
+                tool = atoi(line.cmd().data() + 1);
+            } else if (line.cmd() == "G1" && line.extruding(self) && line.dist_XY(self) > 0) {
+                if (is_approx<double>(line.new_F(self), solid_infill_speed * 60.) && (tool == 0 || tool == 1))
+                    (tool == 0 ? T0_shells : T1_shells).insert(scaled<coord_t>(self.z()));
+            }
+        });
+        return std::make_pair(T0_shells, T1_shells);
+    };
+    
+    WHEN("Interface shells disabled") {
+        std::string gcode = slice_stacked_cubes(config, lower_config, upper_config);
+        auto [t0, t1] = test_shells(gcode);
+        THEN("no interface shells") {
+            REQUIRE(t0.empty());
+            REQUIRE(t1.empty());
+        }
+    }
+    WHEN("Interface shells enabled") {
+        config.set_deserialize_strict("interface_shells", "1");
+        std::string gcode = slice_stacked_cubes(config, lower_config, upper_config);
+        auto [t0, t1] = test_shells(gcode);
+        THEN("top interface shells") {
+            REQUIRE(t0.size() == lower_config.opt_int("top_solid_layers"));
+        }
+        THEN("bottom interface shells") {
+            REQUIRE(t1.size() == upper_config.opt_int("bottom_solid_layers"));
+        }
+    }
+    WHEN("Slicing with auto-assigned extruders") {
+        auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+            { "nozzle_diameter",        "0.6,0.6,0.6,0.6" },
+            { "layer_height",           0.4 },
+            { "first_layer_height",     0.4 },
+            { "skirts",                 0 }
+        });
+        std::string gcode = slice_stacked_cubes(config, DynamicPrintConfig{}, DynamicPrintConfig{});
+        GCodeReader       parser;
+        int               tool = -1;
+        // Scaled Z heights.
+        std::set<coord_t> T0_shells, T1_shells;
+        parser.parse_buffer(gcode, [&tool, &T0_shells, &T1_shells](Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+        {
+            if (boost::starts_with(line.cmd(), "T")) {
+                tool = atoi(line.cmd().data() + 1);
+            } else if (line.cmd() == "G1" && line.extruding(self) && line.dist_XY(self) > 0) {
+                if (tool == 0 && self.z() > 20)
+                    // Layers incorrectly extruded with T0 at the top object.
+                    T0_shells.insert(scaled<coord_t>(self.z()));
+                else if (tool == 1 && self.z() < 20)
+                    // Layers incorrectly extruded with T1 at the bottom object.
+                    T1_shells.insert(scaled<coord_t>(self.z()));
+            }
+        });
+        THEN("T0 is never used for upper object") {
+            REQUIRE(T0_shells.empty());
+        }
+        THEN("T0 is never used for lower object") {
+            REQUIRE(T1_shells.empty());
+        }
+    }
+}
diff --git a/tests/fff_print/test_perimeters.cpp b/tests/fff_print/test_perimeters.cpp
new file mode 100644
index 000000000..a3f11113a
--- /dev/null
+++ b/tests/fff_print/test_perimeters.cpp
@@ -0,0 +1,599 @@
+#include <catch2/catch.hpp>
+
+#include <numeric>
+#include <sstream>
+
+#include "libslic3r/Config.hpp"
+#include "libslic3r/ClipperUtils.hpp"
+#include "libslic3r/Layer.hpp"
+#include "libslic3r/PerimeterGenerator.hpp"
+#include "libslic3r/Print.hpp"
+#include "libslic3r/PrintConfig.hpp"
+#include "libslic3r/SurfaceCollection.hpp"
+#include "libslic3r/libslic3r.h"
+
+#include "test_data.hpp"
+
+using namespace Slic3r;
+
+SCENARIO("Perimeter nesting", "[Perimeters]")
+{
+    struct TestData {
+        ExPolygons          expolygons;
+        // expected number of loops
+        int                 total;
+        // expected number of external loops
+        int                 external;
+        // expected external perimeter
+        std::vector<bool>   ext_order;
+        // expected number of internal contour loops
+        int                 cinternal;
+        // expected number of ccw loops
+        int                 ccw;
+        // expected ccw/cw order
+        std::vector<bool>   ccw_order;
+        // expected nesting order
+        std::vector<std::vector<int>> nesting;
+    };
+
+    FullPrintConfig config;
+
+    auto test = [&config](const TestData &data) {
+        SurfaceCollection slices;
+        slices.append(data.expolygons, stInternal);
+        
+        ExtrusionEntityCollection loops;
+        ExtrusionEntityCollection gap_fill;
+        SurfaceCollection         fill_surfaces;
+        PerimeterGenerator        perimeter_generator(
+            &slices, 
+            1., // layer height
+            Flow(1., 1., 1.),
+            static_cast<const PrintRegionConfig*>(&config),
+            static_cast<const PrintObjectConfig*>(&config),
+            static_cast<const PrintConfig*>(&config),
+            false, // spiral_vase
+            // output:
+            &loops, &gap_fill, &fill_surfaces);
+        perimeter_generator.process();
+
+        THEN("expected number of collections") {
+            REQUIRE(loops.entities.size() == data.expolygons.size());
+        }        
+        
+        loops = loops.flatten();
+        THEN("expected number of loops") {
+            REQUIRE(loops.entities.size() == data.total);
+        }
+        THEN("expected number of external loops") {
+            size_t num_external = std::count_if(loops.entities.begin(), loops.entities.end(), 
+                [](const ExtrusionEntity *ee){ return ee->role() == erExternalPerimeter; });
+            REQUIRE(num_external == data.external);
+        }
+        THEN("expected external order") {
+            std::vector<bool> ext_order;
+            for (auto *ee : loops.entities)
+                ext_order.emplace_back(ee->role() == erExternalPerimeter);
+            REQUIRE(ext_order == data.ext_order);
+        }
+        THEN("expected number of internal contour loops") {
+            size_t cinternal = std::count_if(loops.entities.begin(), loops.entities.end(), 
+                [](const ExtrusionEntity *ee){ return dynamic_cast<const ExtrusionLoop*>(ee)->loop_role() == elrContourInternalPerimeter; });
+            REQUIRE(cinternal == data.cinternal);
+        }
+        THEN("expected number of ccw loops") {
+            size_t ccw = std::count_if(loops.entities.begin(), loops.entities.end(), 
+                [](const ExtrusionEntity *ee){ return dynamic_cast<const ExtrusionLoop*>(ee)->polygon().is_counter_clockwise(); });
+            REQUIRE(ccw == data.ccw);
+        }
+        THEN("expected ccw/cw order") {
+            std::vector<bool> ccw_order;
+            for (auto *ee : loops.entities)
+                ccw_order.emplace_back(dynamic_cast<const ExtrusionLoop*>(ee)->polygon().is_counter_clockwise());
+            REQUIRE(ccw_order == data.ccw_order);
+        }
+        THEN("expected nesting order") {
+            for (const std::vector<int> &nesting : data.nesting) {
+                for (size_t i = 1; i < nesting.size(); ++ i)
+                    REQUIRE(dynamic_cast<const ExtrusionLoop*>(loops.entities[nesting[i - 1]])->polygon().contains(loops.entities[nesting[i]]->first_point()));
+            }
+        }
+    };
+
+    WHEN("Rectangle") {
+        config.perimeters.value = 3;
+        TestData data;
+        data.expolygons  = { 
+            ExPolygon{ Polygon::new_scale({ {0,0}, {100,0}, {100,100}, {0,100} }) }
+        };
+        data.total       = 3;
+        data.external    = 1;
+        data.ext_order   = { false, false, true };
+        data.cinternal   = 1;
+        data.ccw         = 3;
+        data.ccw_order   = { true, true, true };
+        data.nesting     = { { 2, 1, 0 } };
+        test(data);
+    }
+    WHEN("Rectangle with hole") {
+        config.perimeters.value = 3;
+        TestData data;
+        data.expolygons  = { 
+            ExPolygon{ Polygon::new_scale({ {0,0}, {100,0}, {100,100}, {0,100} }), 
+                       Polygon::new_scale({ {40,40}, {40,60}, {60,60}, {60,40} }) } 
+        };
+        data.total       = 6;
+        data.external    = 2;
+        data.ext_order   = { false, false, true, false, false, true };
+        data.cinternal   = 1;
+        data.ccw         = 3;
+        data.ccw_order   = { false, false, false, true, true, true };
+        data.nesting     = { { 5, 4, 3, 0, 1, 2 } };
+        test(data);
+    }
+    WHEN("Nested rectangles with holes") {
+        config.perimeters.value = 3;
+        TestData data;
+        data.expolygons  = {
+            ExPolygon{ Polygon::new_scale({ {0,0}, {200,0}, {200,200}, {0,200} }), 
+                       Polygon::new_scale({ {20,20}, {20,180}, {180,180}, {180,20} }) },
+            ExPolygon{ Polygon::new_scale({ {50,50}, {150,50}, {150,150}, {50,150} }), 
+                       Polygon::new_scale({ {80,80}, {80,120}, {120,120}, {120,80} }) }
+        };
+        data.total       = 4*3;
+        data.external    = 4;
+        data.ext_order   = { false, false, true, false, false, true, false, false, true, false, false, true };
+        data.cinternal   = 2;
+        data.ccw         = 2*3;
+        data.ccw_order   = { false, false, false, true, true, true, false, false, false, true, true, true };
+        test(data);
+    }
+    WHEN("Rectangle with multiple holes") {
+        config.perimeters.value = 2;
+        TestData data;
+        ExPolygon expoly{ Polygon::new_scale({ {0,0}, {50,0}, {50,50}, {0,50} }) };
+        expoly.holes.emplace_back(Polygon::new_scale({ {7.5,7.5},  {7.5,12.5},  {12.5,12.5}, {12.5,7.5}  }));
+        expoly.holes.emplace_back(Polygon::new_scale({ {7.5,17.5}, {7.5,22.5},  {12.5,22.5}, {12.5,17.5} }));
+        expoly.holes.emplace_back(Polygon::new_scale({ {7.5,27.5}, {7.5,32.5},  {12.5,32.5}, {12.5,27.5} }));
+        expoly.holes.emplace_back(Polygon::new_scale({ {7.5,37.5}, {7.5,42.5},  {12.5,42.5}, {12.5,37.5} }));
+        expoly.holes.emplace_back(Polygon::new_scale({ {17.5,7.5}, {17.5,12.5}, {22.5,12.5}, {22.5,7.5}  }));
+        data.expolygons  = { expoly };
+        data.total       = 12;
+        data.external    = 6;
+        data.ext_order   = { false, true, false, true, false, true, false, true, false, true, false, true };
+        data.cinternal   = 1;
+        data.ccw         = 2;
+        data.ccw_order   = { false, false, false, false, false, false, false, false, false, false, true, true };
+        data.nesting     = { {0,1},{2,3},{4,5},{6,7},{8,9} };
+        test(data);
+    };
+}
+
+SCENARIO("Perimeters", "[Perimeters]")
+{
+    auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+        { "skirts",                 0 },
+        { "fill_density",           0 },
+        { "perimeters",             3 },
+        { "top_solid_layers",       0 },
+        { "bottom_solid_layers",    0 },
+        // to prevent speeds from being altered
+        { "cooling",                "0" },
+        // to prevent speeds from being altered
+        { "first_layer_speed",      "100%" }
+    });
+
+    WHEN("Bridging perimeters disabled") {
+        std::string gcode = Slic3r::Test::slice({ Slic3r::Test::TestMesh::overhang }, config);
+
+        THEN("all perimeters extruded ccw") {
+            GCodeReader parser;
+            bool        has_cw_loops = false;
+            Polygon     current_loop;
+            parser.parse_buffer(gcode, [&has_cw_loops, &current_loop](Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+            {
+                if (line.extruding(self) && line.dist_XY(self) > 0) {
+                    if (current_loop.empty())
+                        current_loop.points.emplace_back(self.xy_scaled());
+                    current_loop.points.emplace_back(line.new_XY_scaled(self));
+                } else if (! line.cmd_is("M73")) {
+                    // skips remaining time lines (M73)
+                    if (! current_loop.empty() && current_loop.is_clockwise())
+                        has_cw_loops = true;
+                    current_loop.clear();
+                }
+            });
+            REQUIRE(! has_cw_loops);
+        }
+    }
+    
+    auto test = [&config](Test::TestMesh model) {    
+        // we test two copies to make sure ExtrusionLoop objects are not modified in-place (the second object would not detect cw loops and thus would calculate wrong)
+        std::string gcode = Slic3r::Test::slice({ model, model }, config);
+        GCodeReader parser;
+        bool        has_cw_loops = false;
+        bool        has_outwards_move = false;
+        bool        starts_on_convex_point = false;
+        // print_z => count of external loops
+        std::map<coord_t, int> external_loops;
+        Polygon     current_loop;
+        const double external_perimeter_speed = config.get_abs_value("external_perimeter_speed") * 60.;
+        parser.parse_buffer(gcode, [&has_cw_loops, &has_outwards_move, &starts_on_convex_point, &external_loops, &current_loop, external_perimeter_speed, model]
+            (Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+        {
+            if (line.extruding(self) && line.dist_XY(self) > 0) {
+                if (current_loop.empty())
+                    current_loop.points.emplace_back(self.xy_scaled());
+                current_loop.points.emplace_back(line.new_XY_scaled(self));
+            } else if (! line.cmd_is("M73")) {
+                // skips remaining time lines (M73)
+                if (! current_loop.empty()) {
+                    if (current_loop.is_clockwise())
+                        has_cw_loops = true;
+                    if (is_approx<double>(self.f(), external_perimeter_speed)) {
+                        // reset counter for second object
+                        coord_t z = scaled<coord_t>(self.z());
+                        auto it = external_loops.find(z);
+                        if (it == external_loops.end())
+                            it = external_loops.insert(std::make_pair(z, 0)).first;
+                        else if (it->second == 2)
+                            it->second = 0;
+                        ++ it->second;
+                        bool is_contour          = it->second == 2;
+                        bool is_hole             = it->second == 1;
+                        // Testing whether the move point after loop ends up inside the extruded loop.
+                        bool loop_contains_point = current_loop.contains(line.new_XY_scaled(self));
+                        if (// contour should include destination
+                            (! loop_contains_point && is_contour) ||
+                            // hole should not
+                            (loop_contains_point && is_hole))
+                            has_outwards_move = true;
+                        if (model == Test::TestMesh::cube_with_concave_hole) {
+                            // check that loop starts at a concave vertex
+                            double cross = cross2((current_loop.points.front() - current_loop.points[current_loop.points.size() - 2]).cast<double>(), (current_loop.points[1] - current_loop.points.front()).cast<double>());
+                            bool   convex = cross > 0.;
+                            if ((convex && is_contour) || (! convex && is_hole))
+                                starts_on_convex_point = true;
+                        }
+                    }
+                    current_loop.clear();
+                }
+            }
+        });
+        THEN("all perimeters extruded ccw") {
+            REQUIRE(! has_cw_loops);
+        }
+        THEN("move inwards after completing external loop") {
+            REQUIRE(! has_outwards_move);
+        }
+        THEN("loops start on concave point if any") {
+            REQUIRE(! starts_on_convex_point);
+        }
+
+    };
+    // Reusing the config above.
+    config.set_deserialize_strict({
+        { "external_perimeter_speed", 68 }
+    });
+    GIVEN("Cube with hole") { test(Test::TestMesh::cube_with_hole); }
+    GIVEN("Cube with concave hole") { test(Test::TestMesh::cube_with_concave_hole); }
+    
+    WHEN("Bridging perimeters enabled") {
+        // Reusing the config above.
+        config.set_deserialize_strict({
+            { "perimeters",                 1 },
+            { "perimeter_speed",            77 },
+            { "external_perimeter_speed",   66 },
+            { "bridge_speed",               99 },
+            { "cooling",                    "1" },
+            { "fan_below_layer_time",       "0" },
+            { "slowdown_below_layer_time",  "0" },
+            { "bridge_fan_speed",           "100" },
+            // arbitrary value
+            { "bridge_flow_ratio",          33 },
+            { "overhangs",                  true }
+        });
+    
+        std::string gcode = Slic3r::Test::slice({ mesh(Slic3r::Test::TestMesh::overhang) }, config);
+
+        THEN("Bridging is applied to bridging perimeters") {
+            GCodeReader  parser;
+            // print Z => speeds
+            std::map<coord_t, std::set<double>> layer_speeds;
+            int          fan_speed = 0;
+            const double perimeter_speed            = config.opt_float("perimeter_speed") * 60.;
+            const double external_perimeter_speed   = config.get_abs_value("external_perimeter_speed") * 60.;
+            const double bridge_speed               = config.opt_float("bridge_speed") * 60.;
+            const double nozzle_dmr                 = config.opt<ConfigOptionFloats>("nozzle_diameter")->get_at(0);
+            const double filament_dmr               = config.opt<ConfigOptionFloats>("filament_diameter")->get_at(0);
+            const double bridge_mm_per_mm           = sqr(nozzle_dmr / filament_dmr) * config.opt_float("bridge_flow_ratio");
+            parser.parse_buffer(gcode, [&layer_speeds, &fan_speed, perimeter_speed, external_perimeter_speed, bridge_speed, nozzle_dmr, filament_dmr, bridge_mm_per_mm]
+                (Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+            {
+                if (line.cmd_is("M107"))
+                    fan_speed = 0;
+                else if (line.cmd_is("M106"))
+                    line.has_value('S', fan_speed);
+                else if (line.extruding(self) && line.dist_XY(self) > 0) {
+                    double feedrate = line.new_F(self);
+                    REQUIRE((is_approx(feedrate, perimeter_speed) || is_approx(feedrate, external_perimeter_speed) || is_approx(feedrate, bridge_speed)));
+                    layer_speeds[self.z()].insert(feedrate);
+                    bool   bridging  = is_approx(feedrate, bridge_speed);
+                    double mm_per_mm = line.dist_E(self) / line.dist_XY(self);
+                    // Fan enabled at full speed when bridging, disabled when not bridging.
+                    REQUIRE((! bridging || fan_speed == 255));
+                    REQUIRE((bridging || fan_speed == 0));
+                    // When bridging, bridge flow is applied.
+                    REQUIRE((! bridging || std::abs(mm_per_mm - bridge_mm_per_mm) <= 0.01));
+                }
+            });
+            // only overhang layer has more than one speed
+            size_t num_overhangs = std::count_if(layer_speeds.begin(), layer_speeds.end(), [](const std::pair<double, std::set<double>> &v){ return v.second.size() > 1; });
+            REQUIRE(num_overhangs == 1);
+        }
+    }
+
+    GIVEN("iPad stand") {
+        WHEN("Extra perimeters enabled") {
+            auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+                { "skirts",                     0 },
+                { "perimeters",                 3 },
+                { "layer_height",               0.4 },
+                { "first_layer_height",         0.35 },
+                { "extra_perimeters",           1 },
+                // to prevent speeds from being altered
+                { "cooling",                    "0" },
+                // to prevent speeds from being altered
+                { "first_layer_speed",          "100%" },
+                { "perimeter_speed",            99 },
+                { "external_perimeter_speed",   99 },
+                { "small_perimeter_speed",      99 },
+                { "thin_walls",                 0 },
+            });
+        
+            std::string gcode = Slic3r::Test::slice({ Slic3r::Test::TestMesh::ipadstand }, config);
+            // z => number of loops
+            std::map<coord_t, int> perimeters;
+            bool                   in_loop         = false;
+            const double           perimeter_speed = config.opt_float("perimeter_speed") * 60.;
+            GCodeReader            parser;
+            parser.parse_buffer(gcode, [&perimeters, &in_loop, perimeter_speed](Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+            {
+                if (line.extruding(self) && line.dist_XY(self) > 0 && is_approx<double>(line.new_F(self), perimeter_speed)) {
+                    if (! in_loop) {
+                        coord_t z = scaled<coord_t>(self.z());
+                        auto it = perimeters.find(z);
+                        if (it == perimeters.end())
+                            it = perimeters.insert(std::make_pair(z, 0)).first;
+                        ++ it->second;
+                    }
+                    in_loop = true;
+                } else if (! line.cmd_is("M73")) {
+                    // skips remaining time lines (M73)
+                    in_loop = false;
+                }
+            });
+            THEN("no superfluous extra perimeters") {
+                const int num_perimeters = config.opt_int("perimeters");
+                size_t extra_perimeters = std::count_if(perimeters.begin(), perimeters.end(), [num_perimeters](const std::pair<const coord_t, int> &v){ return (v.second % num_perimeters) > 0; });
+                REQUIRE(extra_perimeters == 0);
+            }
+        }
+    }
+}
+
+SCENARIO("Some weird coverage test", "[Perimeters]")
+{
+    auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+        { "nozzle_diameter",                    "0.4" },
+        { "perimeters",                         2 },
+        { "perimeter_extrusion_width",          0.4 },
+        { "external_perimeter_extrusion_width", 0.4 },
+        { "infill_extrusion_width",             0.53 },
+        { "solid_infill_extrusion_width",       0.53 }
+    });
+
+    // we just need a pre-filled Print object
+    Print print;
+    Model model;
+    Slic3r::Test::init_print({ Test::TestMesh::cube_20x20x20 }, print, model, config);
+    
+    // override a layer's slices
+    ExPolygon expolygon;
+    expolygon.contour = {
+        {-71974463,-139999376},{-71731792,-139987456},{-71706544,-139985616},{-71682119,-139982639},{-71441248,-139946912},{-71417487,-139942895},{-71379384,-139933984},{-71141800,-139874480},
+        {-71105247,-139862895},{-70873544,-139779984},{-70838592,-139765856},{-70614943,-139660064},{-70581783,-139643567},{-70368368,-139515680},{-70323751,-139487872},{-70122160,-139338352},
+        {-70082399,-139306639},{-69894800,-139136624},{-69878679,-139121327},{-69707992,-138933008},{-69668575,-138887343},{-69518775,-138685359},{-69484336,-138631632},{-69356423,-138418207},
+        {-69250040,-138193296},{-69220920,-138128976},{-69137992,-137897168},{-69126095,-137860255},{-69066568,-137622608},{-69057104,-137582511},{-69053079,-137558751},{-69017352,-137317872},
+        {-69014392,-137293456},{-69012543,-137268207},{-68999369,-137000000},{-63999999,-137000000},{-63705947,-136985551},{-63654984,-136977984},{-63414731,-136942351},{-63364756,-136929840},
+        {-63129151,-136870815},{-62851950,-136771631},{-62585807,-136645743},{-62377483,-136520895},{-62333291,-136494415},{-62291908,-136463728},{-62096819,-136319023},{-62058644,-136284432},
+        {-61878676,-136121328},{-61680968,-135903184},{-61650275,-135861807},{-61505591,-135666719},{-61354239,-135414191},{-61332211,-135367615},{-61228359,-135148063},{-61129179,-134870847},
+        {-61057639,-134585262},{-61014451,-134294047},{-61000000,-134000000},{-61000000,-107999999},{-61014451,-107705944},{-61057639,-107414736},{-61129179,-107129152},{-61228359,-106851953},
+        {-61354239,-106585808},{-61505591,-106333288},{-61680967,-106096816},{-61878675,-105878680},{-62096820,-105680967},{-62138204,-105650279},{-62333292,-105505591},{-62585808,-105354239},
+        {-62632384,-105332207},{-62851951,-105228360},{-62900463,-105211008},{-63129152,-105129183},{-63414731,-105057640},{-63705947,-105014448},{-63999999,-105000000},{-68999369,-105000000},
+        {-69012543,-104731792},{-69014392,-104706544},{-69017352,-104682119},{-69053079,-104441248},{-69057104,-104417487},{-69066008,-104379383},{-69125528,-104141799},{-69137111,-104105248},
+        {-69220007,-103873544},{-69234136,-103838591},{-69339920,-103614943},{-69356415,-103581784},{-69484328,-103368367},{-69512143,-103323752},{-69661647,-103122160},{-69693352,-103082399},
+        {-69863383,-102894800},{-69878680,-102878679},{-70066999,-102707992},{-70112656,-102668576},{-70314648,-102518775},{-70368367,-102484336},{-70581783,-102356424},{-70806711,-102250040},
+        {-70871040,-102220919},{-71102823,-102137992},{-71139752,-102126095},{-71377383,-102066568},{-71417487,-102057104},{-71441248,-102053079},{-71682119,-102017352},{-71706535,-102014392},
+        {-71731784,-102012543},{-71974456,-102000624},{-71999999,-102000000},{-104000000,-102000000},{-104025536,-102000624},{-104268207,-102012543},{-104293455,-102014392},
+        {-104317880,-102017352},{-104558751,-102053079},{-104582512,-102057104},{-104620616,-102066008},{-104858200,-102125528},{-104894751,-102137111},{-105126455,-102220007},
+        {-105161408,-102234136},{-105385056,-102339920},{-105418215,-102356415},{-105631632,-102484328},{-105676247,-102512143},{-105877839,-102661647},{-105917600,-102693352},
+        {-106105199,-102863383},{-106121320,-102878680},{-106292007,-103066999},{-106331424,-103112656},{-106481224,-103314648},{-106515663,-103368367},{-106643575,-103581783},
+        {-106749959,-103806711},{-106779080,-103871040},{-106862007,-104102823},{-106873904,-104139752},{-106933431,-104377383},{-106942896,-104417487},{-106946920,-104441248},
+        {-106982648,-104682119},{-106985607,-104706535},{-106987456,-104731784},{-107000630,-105000000},{-112000000,-105000000},{-112294056,-105014448},{-112585264,-105057640},
+        {-112870848,-105129184},{-112919359,-105146535},{-113148048,-105228360},{-113194624,-105250392},{-113414191,-105354239},{-113666711,-105505591},{-113708095,-105536279},
+        {-113903183,-105680967},{-114121320,-105878679},{-114319032,-106096816},{-114349720,-106138200},{-114494408,-106333288},{-114645760,-106585808},{-114667792,-106632384},
+        {-114771640,-106851952},{-114788991,-106900463},{-114870815,-107129151},{-114942359,-107414735},{-114985551,-107705943},{-115000000,-107999999},{-115000000,-134000000},
+        {-114985551,-134294048},{-114942359,-134585263},{-114870816,-134870847},{-114853464,-134919359},{-114771639,-135148064},{-114645759,-135414192},{-114494407,-135666720},
+        {-114319031,-135903184},{-114121320,-136121327},{-114083144,-136155919},{-113903184,-136319023},{-113861799,-136349712},{-113666711,-136494416},{-113458383,-136619264},
+        {-113414192,-136645743},{-113148049,-136771631},{-112870848,-136870815},{-112820872,-136883327},{-112585264,-136942351},{-112534303,-136949920},{-112294056,-136985551},
+        {-112000000,-137000000},{-107000630,-137000000},{-106987456,-137268207},{-106985608,-137293440},{-106982647,-137317872},{-106946920,-137558751},{-106942896,-137582511},
+        {-106933991,-137620624},{-106874471,-137858208},{-106862888,-137894751},{-106779992,-138126463},{-106765863,-138161424},{-106660080,-138385055},{-106643584,-138418223},
+        {-106515671,-138631648},{-106487855,-138676256},{-106338352,-138877839},{-106306647,-138917600},{-106136616,-139105199},{-106121320,-139121328},{-105933000,-139291999},
+        {-105887344,-139331407},{-105685351,-139481232},{-105631632,-139515663},{-105418216,-139643567},{-105193288,-139749951},{-105128959,-139779072},{-104897175,-139862016},
+        {-104860247,-139873904},{-104622616,-139933423},{-104582511,-139942896},{-104558751,-139946912},{-104317880,-139982656},{-104293463,-139985616},{-104268216,-139987456},
+        {-104025544,-139999376},{-104000000,-140000000},{-71999999,-140000000}
+    };
+    expolygon.holes = {
+        {{-105000000,-138000000},{-105000000,-104000000},{-71000000,-104000000},{-71000000,-138000000}},
+        {{-69000000,-132000000},{-69000000,-110000000},{-64991180,-110000000},{-64991180,-132000000}},
+        {{-111008824,-132000000},{-111008824,-110000000},{-107000000,-110000000},{-107000000,-132000000}}
+    };
+    PrintObject *object = print.get_object(0);
+    object->slice();
+    Layer       *layer = object->get_layer(1);
+    LayerRegion *layerm = layer->get_region(0);
+    layerm->slices.clear();
+    layerm->slices.append({ expolygon }, stInternal);
+    
+    // make perimeters
+    layer->make_perimeters();
+    
+    // compute the covered area
+    Flow pflow = layerm->flow(frPerimeter);
+    Flow iflow = layerm->flow(frInfill);
+    Polygons covered_by_perimeters;
+    Polygons covered_by_infill;
+    {
+        Polygons acc;
+        for (const ExtrusionEntity *ee : layerm->perimeters.entities)
+            for (const ExtrusionEntity *ee : dynamic_cast<const ExtrusionEntityCollection*>(ee)->entities)
+                append(acc, offset(dynamic_cast<const ExtrusionLoop*>(ee)->polygon().split_at_first_point(), float(pflow.scaled_width() / 2.f + SCALED_EPSILON)));
+        covered_by_perimeters = union_(acc);
+    }
+    {
+        Polygons acc;
+        for (const Surface &surface : layerm->fill_surfaces.surfaces)
+            append(acc, to_polygons(surface.expolygon));
+        for (const ExtrusionEntity *ee : layerm->thin_fills.entities)
+            append(acc, offset(dynamic_cast<const ExtrusionPath*>(ee)->polyline, float(iflow.scaled_width() / 2.f + SCALED_EPSILON)));
+        covered_by_infill = union_(acc);
+    }
+    
+    // compute the non covered area
+    ExPolygons non_covered = diff_ex(to_polygons(layerm->slices.surfaces), union_(covered_by_perimeters, covered_by_infill));
+    
+    /*
+    if (0) {
+        printf "max non covered = %f\n", List::Util::max(map unscale unscale $_->area, @$non_covered);
+        require "Slic3r/SVG.pm";
+        Slic3r::SVG::output(
+            "gaps.svg",
+            expolygons          => [ map $_->expolygon, @{$layerm->slices} ],
+            red_expolygons      => union_ex([ map @$_, (@$covered_by_perimeters, @$covered_by_infill) ]),
+            green_expolygons    => union_ex($non_covered),
+            no_arrows           => 1,
+            polylines           => [
+                map $_->polygon->split_at_first_point, map @$_, @{$layerm->perimeters},
+            ],
+        );
+    }
+    */
+    THEN("no gap between perimeters and infill") {
+        size_t num_non_convered = std::count_if(non_covered.begin(), non_covered.end(), [&iflow](const ExPolygon &ex){ return ex.area() > sqr(double(iflow.scaled_width())); });
+        REQUIRE(num_non_convered == 0);
+    }
+}
+
+SCENARIO("Perimeters3", "[Perimeters]")
+{
+    auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+        { "skirts",                 0 },
+        { "perimeters",             3 },
+        { "layer_height",           0.4 },
+        { "bridge_speed",           99 },
+        // to prevent bridging over sparse infill
+        { "fill_density",           0 },
+        { "overhangs",              true },
+        // to prevent speeds from being altered
+        { "cooling",                "0" },
+        // to prevent speeds from being altered
+        { "first_layer_speed",      "100%" }
+    });
+
+    auto test = [&config](const Vec3d &scale) {
+        std::string         gcode = Slic3r::Test::slice({ mesh(Slic3r::Test::TestMesh::V, Vec3d::Zero(), scale) }, config);
+        GCodeReader         parser;
+        std::set<coord_t>   z_with_bridges;
+        const double        bridge_speed = config.opt_float("bridge_speed") * 60.;
+        parser.parse_buffer(gcode, [&z_with_bridges, bridge_speed](Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+        {
+            if (line.extruding(self) && line.dist_XY(self) > 0 && is_approx<double>(line.new_F(self), bridge_speed))
+                z_with_bridges.insert(scaled<coord_t>(self.z()));
+        });
+        return z_with_bridges.size();
+    };
+
+    GIVEN("V shape, unscaled") {
+        int n = test(Vec3d(1., 1., 1.));
+        // except for the two internal solid layers above void
+        THEN("no overhangs printed with bridge speed") {
+            REQUIRE(n == 1);
+        }
+    }
+    GIVEN("V shape, scaled 3x in X") {
+        int n = test(Vec3d(3., 1., 1.));
+        // except for the two internal solid layers above void
+        THEN("overhangs printed with bridge speed") {
+            REQUIRE(n > 2);
+        }
+    }
+}
+
+SCENARIO("Perimeters4", "[Perimeters]")
+{
+    auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+        { "seam_position",        "random" }
+    });
+    std::string gcode = Slic3r::Test::slice({ Slic3r::Test::TestMesh::cube_20x20x20 }, config);
+    THEN("successful generation of G-code with seam_position = random") {
+        REQUIRE(! gcode.empty());
+    }
+}
+
+SCENARIO("Seam alignment", "[Perimeters]")
+{
+    auto test = [](Test::TestMesh model) {
+        auto config = Slic3r::DynamicPrintConfig::full_print_config_with({
+            { "seam_position",          "aligned" },
+            { "skirts",                 0 },
+            { "perimeters",             1 },
+            { "fill_density",           0 },
+            { "top_solid_layers",       0 },
+            { "bottom_solid_layers",    0 },
+            { "retract_layer_change",   "0" }
+        });
+        std::string gcode = Slic3r::Test::slice({ model }, config);
+        bool        was_extruding = false;
+        Points      seam_points;
+        GCodeReader parser;
+        parser.parse_buffer(gcode, [&was_extruding, &seam_points](Slic3r::GCodeReader &self, const Slic3r::GCodeReader::GCodeLine &line)
+        {
+            if (line.extruding(self)) {
+                if (! was_extruding)
+                    seam_points.emplace_back(self.xy_scaled());
+                was_extruding = true;
+            } else if (! line.cmd_is("M73")) {
+                // skips remaining time lines (M73)
+                was_extruding = false;
+            }
+        });
+        THEN("seam is aligned") {
+            size_t num_not_aligned = 0;
+            for (size_t i = 1; i < seam_points.size(); ++ i) {
+                double d = (seam_points[i] - seam_points[i - 1]).cast<double>().norm();
+                // Seams shall be aligned up to 3mm.
+                if (d > scaled<double>(3.))
+                    ++ num_not_aligned;
+            }
+            REQUIRE(num_not_aligned == 0);
+        }
+    };
+
+    GIVEN("20mm cube") {
+        test(Slic3r::Test::TestMesh::cube_20x20x20);
+    }
+    GIVEN("small_dorito") {
+        test(Slic3r::Test::TestMesh::small_dorito);
+    }
+}
diff --git a/tests/fff_print/test_support_material.cpp b/tests/fff_print/test_support_material.cpp
index 442db7654..c5087263c 100644
--- a/tests/fff_print/test_support_material.cpp
+++ b/tests/fff_print/test_support_material.cpp
@@ -236,3 +236,262 @@ SCENARIO("SupportMaterial: Checking bridge speed", "[SupportMaterial]")
 }
 
 #endif
+
+
+/* 
+
+Old Perl tests, which were disabled by Vojtech at the time of first Support Generator refactoring.
+
+#if 0
+{
+    my $config = Slic3r::Config::new_from_defaults;
+    $config->set('support_material', 1);
+    my @contact_z = my @top_z = ();
+    
+    my $test = sub {
+        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+        my $object_config = $print->print->objects->[0]->config;
+        my $flow = Slic3r::Flow->new_from_width(
+            width               => $object_config->support_material_extrusion_width || $object_config->extrusion_width,
+            role                => FLOW_ROLE_SUPPORT_MATERIAL,
+            nozzle_diameter     => $print->config->nozzle_diameter->[$object_config->support_material_extruder-1] // $print->config->nozzle_diameter->[0],
+            layer_height        => $object_config->layer_height,
+        );
+        my $support = Slic3r::Print::SupportMaterial->new(
+            object_config       => $print->print->objects->[0]->config,
+            print_config        => $print->print->config,
+            flow                => $flow,
+            interface_flow      => $flow,
+            first_layer_flow    => $flow,
+        );
+        my $support_z = $support->support_layers_z($print->print->objects->[0], \@contact_z, \@top_z, $config->layer_height);
+        my $expected_top_spacing = $support->contact_distance($config->layer_height, $config->nozzle_diameter->[0]);
+        
+        is $support_z->[0], $config->first_layer_height,
+            'first layer height is honored';
+        is scalar(grep { $support_z->[$_]-$support_z->[$_-1] <= 0 } 1..$#$support_z), 0,
+            'no null or negative support layers';
+        is scalar(grep { $support_z->[$_]-$support_z->[$_-1] > $config->nozzle_diameter->[0] + epsilon } 1..$#$support_z), 0,
+            'no layers thicker than nozzle diameter';
+        
+        my $wrong_top_spacing = 0;
+        foreach my $top_z (@top_z) {
+            # find layer index of this top surface
+            my $layer_id = first { abs($support_z->[$_] - $top_z) < epsilon } 0..$#$support_z;
+            
+            # check that first support layer above this top surface (or the next one) is spaced with nozzle diameter
+            $wrong_top_spacing = 1
+                if ($support_z->[$layer_id+1] - $support_z->[$layer_id]) != $expected_top_spacing
+                && ($support_z->[$layer_id+2] - $support_z->[$layer_id]) != $expected_top_spacing;
+        }
+        ok !$wrong_top_spacing, 'layers above top surfaces are spaced correctly';
+    };
+    
+    $config->set('layer_height', 0.2);
+    $config->set('first_layer_height', 0.3);
+    @contact_z = (1.9);
+    @top_z = (1.1);
+    $test->();
+    
+    $config->set('first_layer_height', 0.4);
+    $test->();
+    
+    $config->set('layer_height', $config->nozzle_diameter->[0]);
+    $test->();
+}
+
+{
+    my $config = Slic3r::Config::new_from_defaults;
+    $config->set('raft_layers', 3);
+    $config->set('brim_width',  0);
+    $config->set('skirts', 0);
+    $config->set('support_material_extruder', 2);
+    $config->set('support_material_interface_extruder', 2);
+    $config->set('layer_height', 0.4);
+    $config->set('first_layer_height', 0.4);
+    my $print = Slic3r::Test::init_print('overhang', config => $config);
+    ok my $gcode = Slic3r::Test::gcode($print), 'no conflict between raft/support and brim';
+    
+    my $tool = 0;
+    Slic3r::GCode::Reader->new->parse($gcode, sub {
+        my ($self, $cmd, $args, $info) = @_;
+        
+        if ($cmd =~ /^T(\d+)/) {
+            $tool = $1;
+        } elsif ($info->{extruding}) {
+            if ($self->Z <= ($config->raft_layers * $config->layer_height)) {
+                fail 'not extruding raft with support material extruder'
+                    if $tool != ($config->support_material_extruder-1);
+            } else {
+                fail 'support material exceeds raft layers'
+                    if $tool == $config->support_material_extruder-1;
+                # TODO: we should test that full support is generated when we use raft too
+            }
+        }
+    });
+}
+
+{
+    my $config = Slic3r::Config::new_from_defaults;
+    $config->set('skirts', 0);
+    $config->set('raft_layers', 3);
+    $config->set('support_material_pattern', 'honeycomb');
+    $config->set('support_material_extrusion_width', 0.6);
+    $config->set('first_layer_extrusion_width', '100%');
+    $config->set('bridge_speed', 99);
+    $config->set('cooling', [ 0 ]);             # prevent speed alteration
+    $config->set('first_layer_speed', '100%');  # prevent speed alteration
+    $config->set('start_gcode', '');            # prevent any unexpected Z move
+    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+    
+    my $layer_id = -1;  # so that first Z move sets this to 0
+    my @raft = my @first_object_layer = ();
+    my %first_object_layer_speeds = ();  # F => 1
+    Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
+        my ($self, $cmd, $args, $info) = @_;
+        
+        if ($info->{extruding} && $info->{dist_XY} > 0) {
+            if ($layer_id <= $config->raft_layers) {
+                # this is a raft layer or the first object layer
+                my $line = Slic3r::Line->new_scale([ $self->X, $self->Y ], [ $info->{new_X}, $info->{new_Y} ]);
+                my @path = @{$line->grow(scale($config->support_material_extrusion_width/2))};
+                if ($layer_id < $config->raft_layers) {
+                    # this is a raft layer
+                    push @raft, @path;
+                } else {
+                    push @first_object_layer, @path;
+                    $first_object_layer_speeds{ $args->{F} // $self->F } = 1;
+                }
+            }
+        } elsif ($cmd eq 'G1' && $info->{dist_Z} > 0) {
+            $layer_id++;
+        }
+    });
+    
+    ok !@{diff(\@first_object_layer, \@raft)},
+        'first object layer is completely supported by raft';
+    is scalar(keys %first_object_layer_speeds), 1,
+        'only one speed used in first object layer';
+    ok +(keys %first_object_layer_speeds)[0] == $config->bridge_speed*60,
+        'bridge speed used in first object layer';
+}
+
+{
+    my $config = Slic3r::Config::new_from_defaults;
+    $config->set('skirts', 0);
+    $config->set('layer_height', 0.35);
+    $config->set('first_layer_height', 0.3);
+    $config->set('nozzle_diameter', [0.5]);
+    $config->set('support_material_extruder', 2);
+    $config->set('support_material_interface_extruder', 2);
+    
+    my $test = sub {
+        my ($raft_layers) = @_;
+        $config->set('raft_layers', $raft_layers);
+        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+        my %raft_z = ();  # z => 1
+        my $tool = undef;
+        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
+            my ($self, $cmd, $args, $info) = @_;
+        
+            if ($cmd =~ /^T(\d+)/) {
+                $tool = $1;
+            } elsif ($info->{extruding} && $info->{dist_XY} > 0) {
+                if ($tool == $config->support_material_extruder-1) {
+                    $raft_z{$self->Z} = 1;
+                }
+            }
+        });
+    
+        is scalar(keys %raft_z), $config->raft_layers, 'correct number of raft layers is generated';
+    };
+    
+    $test->(2);
+    $test->(70);
+    
+    $config->set('layer_height', 0.4);
+    $config->set('first_layer_height', 0.35);
+    $test->(3);
+    $test->(70);
+}
+
+{
+    my $config = Slic3r::Config::new_from_defaults;
+    $config->set('brim_width',  0);
+    $config->set('skirts', 0);
+    $config->set('support_material', 1);
+    $config->set('top_solid_layers', 0); # so that we don't have the internal bridge over infill
+    $config->set('bridge_speed', 99);
+    $config->set('cooling', [ 0 ]);
+    $config->set('first_layer_speed', '100%');
+    
+    my $test = sub {
+        my $print = Slic3r::Test::init_print('overhang', config => $config);
+    
+        my $has_bridge_speed = 0;
+        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
+            my ($self, $cmd, $args, $info) = @_;
+        
+            if ($info->{extruding}) {
+                if (($args->{F} // $self->F) == $config->bridge_speed*60) {
+                    $has_bridge_speed = 1;
+                }
+            }
+        });
+        return $has_bridge_speed;
+    };
+    
+    $config->set('support_material_contact_distance', 0.2);
+    ok $test->(), 'bridge speed is used when support_material_contact_distance > 0';
+    
+    $config->set('support_material_contact_distance', 0);
+    ok !$test->(), 'bridge speed is not used when support_material_contact_distance == 0';
+    
+    $config->set('raft_layers', 5);
+    $config->set('support_material_contact_distance', 0.2);
+    ok $test->(), 'bridge speed is used when raft_layers > 0 and support_material_contact_distance > 0';
+    
+    $config->set('support_material_contact_distance', 0);
+    ok !$test->(), 'bridge speed is not used when raft_layers > 0 and support_material_contact_distance == 0';
+}
+
+{
+    my $config = Slic3r::Config::new_from_defaults;
+    $config->set('skirts', 0);
+    $config->set('start_gcode', '');
+    $config->set('raft_layers', 8);
+    $config->set('nozzle_diameter', [0.4, 1]);
+    $config->set('layer_height', 0.1);
+    $config->set('first_layer_height', 0.8);
+    $config->set('support_material_extruder', 2);
+    $config->set('support_material_interface_extruder', 2);
+    $config->set('support_material_contact_distance', 0);
+    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+    ok my $gcode = Slic3r::Test::gcode($print), 'first_layer_height is validated with support material extruder nozzle diameter when using raft layers';
+    
+    my $tool = undef;
+    my @z = (0);
+    my %layer_heights_by_tool = ();  # tool => [ lh, lh... ]
+    Slic3r::GCode::Reader->new->parse($gcode, sub {
+        my ($self, $cmd, $args, $info) = @_;
+    
+        if ($cmd =~ /^T(\d+)/) {
+            $tool = $1;
+        } elsif ($cmd eq 'G1' && exists $args->{Z} && $args->{Z} != $self->Z) {
+            push @z, $args->{Z};
+        } elsif ($info->{extruding} && $info->{dist_XY} > 0) {
+            $layer_heights_by_tool{$tool} ||= [];
+            push @{ $layer_heights_by_tool{$tool} }, $z[-1] - $z[-2];
+        }
+    });
+    
+    ok !defined(first { $_ > $config->nozzle_diameter->[0] + epsilon }
+        @{ $layer_heights_by_tool{$config->perimeter_extruder-1} }),
+        'no object layer is thicker than nozzle diameter';
+    
+    ok !defined(first { abs($_ - $config->layer_height) < epsilon }
+        @{ $layer_heights_by_tool{$config->support_material_extruder-1} }),
+        'no support material layer is as thin as object layers';
+}
+
+*/
diff --git a/tests/libslic3r/test_clipper_utils.cpp b/tests/libslic3r/test_clipper_utils.cpp
index b357d8ca8..24d949be6 100644
--- a/tests/libslic3r/test_clipper_utils.cpp
+++ b/tests/libslic3r/test_clipper_utils.cpp
@@ -301,6 +301,11 @@ SCENARIO("Various Clipper operations - t/clipper.t", "[ClipperUtils]") {
             }
         }
     }
+    GIVEN("line") {
+        THEN("expand by 5") {
+            REQUIRE(offset(Polyline({10,10}, {20,10}), 5).front().area() == Polygon({ {10,5}, {20,5}, {20,15}, {10,15} }).area());
+        }
+    }
 }
 
 template<e_ordering o = e_ordering::OFF, class P, class Tree> 
diff --git a/xs/CMakeLists.txt b/xs/CMakeLists.txt
index 022ba2c01..ab11e4989 100644
--- a/xs/CMakeLists.txt
+++ b/xs/CMakeLists.txt
@@ -45,7 +45,6 @@ set(XSP_DIR ${CMAKE_CURRENT_SOURCE_DIR}/xsp)
 set(XS_XSP_FILES
     ${XSP_DIR}/BoundingBox.xsp
     ${XSP_DIR}/BridgeDetector.xsp
-    ${XSP_DIR}/Clipper.xsp
     ${XSP_DIR}/Config.xsp
     ${XSP_DIR}/ExPolygon.xsp
     ${XSP_DIR}/ExPolygonCollection.xsp
@@ -59,12 +58,9 @@ set(XS_XSP_FILES
     ${XSP_DIR}/Layer.xsp
     ${XSP_DIR}/Line.xsp
     ${XSP_DIR}/Model.xsp
-    ${XSP_DIR}/PerimeterGenerator.xsp
-    ${XSP_DIR}/PlaceholderParser.xsp
     ${XSP_DIR}/Point.xsp
     ${XSP_DIR}/Polygon.xsp
     ${XSP_DIR}/Polyline.xsp
-    ${XSP_DIR}/PolylineCollection.xsp
     ${XSP_DIR}/Print.xsp
     ${XSP_DIR}/Surface.xsp
     ${XSP_DIR}/SurfaceCollection.xsp
diff --git a/xs/lib/Slic3r/XS.pm b/xs/lib/Slic3r/XS.pm
index 83bc0ee70..9a0181b65 100644
--- a/xs/lib/Slic3r/XS.pm
+++ b/xs/lib/Slic3r/XS.pm
@@ -4,21 +4,6 @@ use strict;
 
 our $VERSION = '0.01';
 
-# We have to load these modules in order to have Wx.pm find the correct paths
-# for wxWidgets dlls on MSW.
-# We avoid loading these on OS X because Wx::Load() initializes a Wx App
-# automatically and it steals focus even when we're not running Slic3r in GUI mode.
-# TODO: only load these when compiling with GUI support
-BEGIN {
-    if ($^O eq 'MSWin32') {
-        eval "use Wx";
-        eval "use Wx::GLCanvas";
-        eval "use Wx::GLContext";
-        eval "use Wx::Html";
-        eval "use Wx::Print";  # because of some Wx bug, thread creation fails if we don't have this (looks like Wx::Printout is hard-coded in some thread cleanup code)
-    }
-}
-
 use Carp qw();
 use XSLoader;
 XSLoader::load(__PACKAGE__, $VERSION);
@@ -58,11 +43,6 @@ use overload
     '@{}' => sub { $_[0]->arrayref },
     'fallback' => 1;
 
-package Slic3r::Polyline::Collection;
-use overload
-    '@{}' => sub { $_[0]->arrayref },
-    'fallback' => 1;
-
 package Slic3r::Polygon;
 use overload
     '@{}' => sub { $_[0]->arrayref },
@@ -197,31 +177,6 @@ sub new {
     return $self;
 }
 
-package Slic3r::Print::SupportMaterial2;
-
-sub new {
-    my ($class, %args) = @_;
-    
-    return $class->_new(
-        $args{print_config},        # required
-        $args{object_config},       # required
-        $args{first_layer_flow},    # required
-        $args{flow},                # required
-        $args{interface_flow},      # required
-        $args{soluble_interface}    // 0
-    );
-}
-
-package Slic3r::GUI::_3DScene::GLVolume::Collection;
-use overload
-    '@{}' => sub { $_[0]->arrayref },
-    'fallback' => 1;
-
-package Slic3r::GUI::PresetCollection;
-use overload
-    '@{}' => sub { $_[0]->arrayref },
-    'fallback' => 1;
-
 package main;
 for my $class (qw(
         Slic3r::BridgeDetector
@@ -240,13 +195,11 @@ for my $class (qw(
         Slic3r::ExtrusionPath::Collection
         Slic3r::Flow
         Slic3r::GCode
-        Slic3r::GCode::PlaceholderParser
         Slic3r::Geometry::BoundingBox
         Slic3r::Geometry::BoundingBoxf
         Slic3r::Geometry::BoundingBoxf3
         Slic3r::Layer
         Slic3r::Layer::Region
-        Slic3r::Layer::Support
         Slic3r::Line
         Slic3r::Linef3
         Slic3r::Model
@@ -264,10 +217,8 @@ for my $class (qw(
         Slic3r::Print
         Slic3r::Print::Object
         Slic3r::Print::Region
-        Slic3r::Print::State
         Slic3r::Surface
         Slic3r::Surface::Collection
-        Slic3r::Print::SupportMaterial2
         Slic3r::TriangleMesh
     ))
 {
diff --git a/xs/src/perlglue.cpp b/xs/src/perlglue.cpp
index 2d996120d..e9f84b8c0 100644
--- a/xs/src/perlglue.cpp
+++ b/xs/src/perlglue.cpp
@@ -13,15 +13,11 @@ REGISTER_CLASS(Flow, "Flow");
 REGISTER_CLASS(CoolingBuffer, "GCode::CoolingBuffer");
 REGISTER_CLASS(GCode, "GCode");
 REGISTER_CLASS(Layer, "Layer");
-REGISTER_CLASS(SupportLayer, "Layer::Support");
 REGISTER_CLASS(LayerRegion, "Layer::Region");
 REGISTER_CLASS(Line, "Line");
 REGISTER_CLASS(Linef3, "Linef3");
-REGISTER_CLASS(PerimeterGenerator, "Layer::PerimeterGenerator");
-REGISTER_CLASS(PlaceholderParser, "GCode::PlaceholderParser");
 REGISTER_CLASS(Polygon, "Polygon");
 REGISTER_CLASS(Polyline, "Polyline");
-REGISTER_CLASS(PolylineCollection, "Polyline::Collection");
 REGISTER_CLASS(Print, "Print");
 REGISTER_CLASS(PrintObject, "Print::Object");
 REGISTER_CLASS(PrintRegion, "Print::Region");
@@ -46,7 +42,6 @@ REGISTER_CLASS(PrintConfig, "Config::Print");
 REGISTER_CLASS(FullPrintConfig, "Config::Full");
 REGISTER_CLASS(Surface, "Surface");
 REGISTER_CLASS(SurfaceCollection, "Surface::Collection");
-REGISTER_CLASS(PrintObjectSupportMaterial, "Print::SupportMaterial2");
 REGISTER_CLASS(TriangleMesh, "TriangleMesh");
 
 SV* ConfigBase__as_hash(ConfigBase* THIS)
diff --git a/xs/t/01_trianglemesh.t b/xs/t/01_trianglemesh.t
index 453cc9218..a071a75a2 100644
--- a/xs/t/01_trianglemesh.t
+++ b/xs/t/01_trianglemesh.t
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 5;
+use Test::More tests => 4;
 
 my $cube = {
     vertices    => [ [20,20,0], [20,0,0], [0,0,0], [0,20,0], [20,20,20], [0,20,20], [0,0,20], [20,0,20] ],
@@ -25,11 +25,6 @@ my $cube = {
         is_deeply $m2->facets, $cube->{facets}, 'cloned facets arrayref roundtrip';
         $m2->scale(3);  # check that it does not affect $m
     }
-    
-    {
-        my $stats = $m->stats;
-        is $stats->{number_of_facets}, scalar(@{ $cube->{facets} }), 'stats.number_of_facets';
-    }
 }
 
 __END__
diff --git a/xs/t/13_polylinecollection.t b/xs/t/13_polylinecollection.t
deleted file mode 100644
index 9b36e7ffa..000000000
--- a/xs/t/13_polylinecollection.t
+++ /dev/null
@@ -1,35 +0,0 @@
-#!/usr/bin/perl
-
-use strict;
-use warnings;
-
-use Slic3r::XS;
-use Test::More tests => 3;
-
-{
-    my $collection = Slic3r::Polyline::Collection->new(
-        Slic3r::Polyline->new([0,15], [0,18], [0,20]),
-        Slic3r::Polyline->new([0,10], [0,8], [0,5]),
-    );
-    is_deeply
-        [ map $_->y, map @$_, @{$collection->chained_path_from(Slic3r::Point->new(0,30), 0)} ],
-        [20, 18, 15, 10, 8, 5],
-        'chained_path_from';
-    is_deeply
-        [ map $_->y, map @$_, @{$collection->chained_path(0)} ],
-        [15, 18, 20, 10, 8, 5],
-        'chained_path';
-}
-
-{
-    my $collection = Slic3r::Polyline::Collection->new(
-        Slic3r::Polyline->new([15,0], [10,0], [4,0]),
-        Slic3r::Polyline->new([10,5], [15,5], [20,5]),
-    );
-    is_deeply
-        [ map $_->x, map @$_, @{$collection->chained_path_from(Slic3r::Point->new(30,0), 0)} ],
-        [reverse 4, 10, 15, 10, 15, 20],
-        'chained_path_from';
-}
-
-__END__
diff --git a/xs/xsp/Clipper.xsp b/xs/xsp/Clipper.xsp
deleted file mode 100644
index 5f9f35906..000000000
--- a/xs/xsp/Clipper.xsp
+++ /dev/null
@@ -1,73 +0,0 @@
-%module{Slic3r::XS};
-
-%{
-#include <xsinit.h>
-#include "libslic3r/ClipperUtils.hpp"
-%}
-
-%package{Slic3r::Geometry::Clipper};
-
-%{
-
-Polygons
-offset(polygons, delta, joinType = Slic3r::ClipperLib::jtMiter, miterLimit = 3)
-    Polygons                polygons
-    const float             delta
-    Slic3r::ClipperLib::JoinType    joinType
-    double                  miterLimit
-    CODE:
-        RETVAL = offset(polygons, delta, joinType, miterLimit);
-    OUTPUT:
-        RETVAL
-
-ExPolygons
-offset2_ex(polygons, delta1, delta2, joinType = Slic3r::ClipperLib::jtMiter, miterLimit = 3)
-    Polygons                polygons
-    const float             delta1
-    const float             delta2
-    Slic3r::ClipperLib::JoinType    joinType
-    double                  miterLimit
-    CODE:
-        RETVAL = offset2_ex(union_ex(polygons), delta1, delta2, joinType, miterLimit);
-    OUTPUT:
-        RETVAL
-
-Polygons
-diff(subject, clip, safety_offset = false)
-    Polygons    subject
-    Polygons    clip
-    bool        safety_offset
-    CODE:
-        RETVAL = diff(subject, clip, safety_offset ? ApplySafetyOffset::Yes : ApplySafetyOffset::No);
-    OUTPUT:
-        RETVAL
-
-ExPolygons
-diff_ex(subject, clip, safety_offset = false)
-    Polygons    subject
-    Polygons    clip
-    bool        safety_offset
-    CODE:
-        RETVAL = diff_ex(subject, clip, safety_offset ? ApplySafetyOffset::Yes : ApplySafetyOffset::No);
-    OUTPUT:
-        RETVAL
-
-Polygons
-union(subject, safety_offset = false)
-    Polygons    subject
-    bool        safety_offset
-    CODE:
-        RETVAL = safety_offset ? union_safety_offset(subject) : union_(subject);
-    OUTPUT:
-        RETVAL
-
-ExPolygons
-union_ex(subject, safety_offset = false)
-    Polygons                    subject
-    bool                        safety_offset
-    CODE:
-        RETVAL = safety_offset ? union_safety_offset_ex(subject) : union_ex(subject);
-    OUTPUT:
-        RETVAL
-
-%}
diff --git a/xs/xsp/Geometry.xsp b/xs/xsp/Geometry.xsp
index e59e8793b..6e808fd8c 100644
--- a/xs/xsp/Geometry.xsp
+++ b/xs/xsp/Geometry.xsp
@@ -47,14 +47,6 @@ convex_hull(points)
     OUTPUT:
         RETVAL
 
-std::vector<Points::size_type>
-chained_path(points)
-    Points      points
-    CODE:
-        RETVAL = chain_points(points);
-    OUTPUT:
-        RETVAL
-
 std::vector<Points::size_type>
 chained_path_from(points, start_from)
     Points      points
diff --git a/xs/xsp/Layer.xsp b/xs/xsp/Layer.xsp
index b97e340bd..4ab7fe188 100644
--- a/xs/xsp/Layer.xsp
+++ b/xs/xsp/Layer.xsp
@@ -65,9 +65,6 @@
     int ptr()
         %code%{ RETVAL = (int)(intptr_t)THIS; %};
     
-    Ref<SupportLayer> as_support_layer()
-        %code%{ RETVAL = dynamic_cast<SupportLayer*>(THIS); %};
-    
     void make_slices();
     void backup_untyped_slices();
     void restore_untyped_slices();
@@ -79,41 +76,3 @@
     void export_region_slices_to_svg_debug(const char *name);
     void export_region_fill_surfaces_to_svg_debug(const char *name);
 };
-
-%name{Slic3r::Layer::Support} class SupportLayer {
-    // owned by PrintObject, no constructor/destructor
-    
-    Ref<Layer> as_layer()
-        %code%{ RETVAL = THIS; %};
-    
-    Ref<ExPolygonCollection> support_islands()
-        %code%{ RETVAL = &THIS->support_islands; %};
-    Ref<ExtrusionEntityCollection> support_fills()
-        %code%{ RETVAL = &THIS->support_fills; %};
-
-    // copies of some Layer methods, because the parameter wrapper code
-    // gets confused about getting a Layer::Support instead of a Layer
-    int id();
-    void set_id(int id);
-    Ref<PrintObject> object();
-    bool slicing_errors()
-        %code%{ RETVAL = THIS->slicing_errors; %};
-    coordf_t slice_z()
-        %code%{ RETVAL = THIS->slice_z; %};
-    coordf_t print_z()
-        %code%{ RETVAL = THIS->print_z; %};
-    coordf_t height()
-        %code%{ RETVAL = THIS->height; %};
-
-    size_t region_count();
-    Ref<LayerRegion> get_region(int idx);
-    Ref<LayerRegion> add_region(PrintRegion* print_region);
-
-    ExPolygonCollection* slices()
-        %code%{ RETVAL = new ExPolygonCollection(THIS->lslices); %};
-    
-    void export_region_slices_to_svg(const char *path);
-    void export_region_fill_surfaces_to_svg(const char *path);
-    void export_region_slices_to_svg_debug(const char *name);
-    void export_region_fill_surfaces_to_svg_debug(const char *name);
-};
diff --git a/xs/xsp/PerimeterGenerator.xsp b/xs/xsp/PerimeterGenerator.xsp
deleted file mode 100644
index a2f589d0b..000000000
--- a/xs/xsp/PerimeterGenerator.xsp
+++ /dev/null
@@ -1,40 +0,0 @@
-%module{Slic3r::XS};
-
-%{
-#include <xsinit.h>
-#include "libslic3r/PerimeterGenerator.hpp"
-#include "libslic3r/Layer.hpp"
-%}
-
-%name{Slic3r::Layer::PerimeterGenerator} class PerimeterGenerator {
-    PerimeterGenerator(SurfaceCollection* slices, double layer_height, Flow* flow,
-        StaticPrintConfig* region_config, StaticPrintConfig* object_config, 
-        StaticPrintConfig* print_config, ExtrusionEntityCollection* loops, 
-        ExtrusionEntityCollection* gap_fill, 
-        SurfaceCollection* fill_surfaces)
-        %code{% RETVAL = new PerimeterGenerator(slices, layer_height, *flow,
-            dynamic_cast<PrintRegionConfig*>(region_config),
-            dynamic_cast<PrintObjectConfig*>(object_config),
-            dynamic_cast<PrintConfig*>(print_config),
-            false,
-            loops, gap_fill, fill_surfaces); %};
-    ~PerimeterGenerator();
-    
-    void set_lower_slices(ExPolygonCollection* lower_slices)
-        %code{% THIS->lower_slices = &lower_slices->expolygons; %};
-    void set_layer_id(int layer_id)
-        %code{% THIS->layer_id = layer_id; %};
-    void set_perimeter_flow(Flow* flow)
-        %code{% THIS->perimeter_flow = *flow; %};
-    void set_ext_perimeter_flow(Flow* flow)
-        %code{% THIS->ext_perimeter_flow = *flow; %};
-    void set_overhang_flow(Flow* flow)
-        %code{% THIS->overhang_flow = *flow; %};
-    void set_solid_infill_flow(Flow* flow)
-        %code{% THIS->solid_infill_flow = *flow; %};
-    
-    Ref<StaticPrintConfig> config()
-        %code{% RETVAL = THIS->config; %};
-    
-    void process();
-};
diff --git a/xs/xsp/PlaceholderParser.xsp b/xs/xsp/PlaceholderParser.xsp
deleted file mode 100644
index 5fa4e33aa..000000000
--- a/xs/xsp/PlaceholderParser.xsp
+++ /dev/null
@@ -1,33 +0,0 @@
-%module{Slic3r::XS};
-
-%{
-#include <xsinit.h>
-#include <vector>
-#include "libslic3r/PlaceholderParser.hpp"
-%}
-
-%name{Slic3r::GCode::PlaceholderParser} class PlaceholderParser {
-    PlaceholderParser();
-    ~PlaceholderParser();
-    
-    void apply_config(DynamicPrintConfig *config)
-        %code%{ THIS->apply_config(*config); %};
-    void set(std::string key, int value);
-    std::string process(std::string str) const
-        %code%{
-            try {
-                RETVAL = THIS->process(str, 0);
-            } catch (std::exception& e) {
-                croak("%s\n", e.what());
-            }
-        %};
-
-    bool evaluate_boolean_expression(const char *str) const
-        %code%{
-            try {
-                RETVAL = THIS->evaluate_boolean_expression(str, THIS->config());
-            } catch (std::exception& e) {
-                croak("%s\n", e.what());
-            }
-        %};        
-};
diff --git a/xs/xsp/Polygon.xsp b/xs/xsp/Polygon.xsp
index 984eb16a9..bc4d412d9 100644
--- a/xs/xsp/Polygon.xsp
+++ b/xs/xsp/Polygon.xsp
@@ -23,7 +23,6 @@
         %code{% RETVAL = THIS->split_at_vertex(*point); %};
     Clone<Polyline> split_at_index(int index);
     Clone<Polyline> split_at_first_point();
-    Points equally_spaced_points(double distance);
     double length();
     double area();
     bool is_counter_clockwise();
diff --git a/xs/xsp/Polyline.xsp b/xs/xsp/Polyline.xsp
index 7846ea5f4..3534e329e 100644
--- a/xs/xsp/Polyline.xsp
+++ b/xs/xsp/Polyline.xsp
@@ -3,7 +3,6 @@
 %{
 #include <xsinit.h>
 #include "libslic3r/BoundingBox.hpp"
-#include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/Polyline.hpp"
 %}
 
@@ -23,7 +22,6 @@
     Lines lines();
     Clone<Point> first_point();
     Clone<Point> last_point();
-    Points equally_spaced_points(double distance);
     double length();
     bool is_valid();
     void clip_end(double distance);
@@ -33,9 +31,7 @@
     void simplify(double tolerance);
     void split_at(Point* point, Polyline* p1, Polyline* p2)
         %code{% THIS->split_at(*point, p1, p2); %};
-    bool is_straight();
     Clone<BoundingBox> bounding_box();
-    void remove_duplicate_points();
 %{
 
 Polyline*
@@ -76,15 +72,5 @@ Polyline::rotate(angle, center_sv)
         from_SV_check(center_sv, &center);
         THIS->rotate(angle, center);
 
-Polygons
-Polyline::grow(delta, joinType = Slic3r::ClipperLib::jtSquare, miterLimit = 3)
-    const float             delta
-    Slic3r::ClipperLib::JoinType    joinType
-    double                  miterLimit
-    CODE:
-        RETVAL = offset(*THIS, delta, joinType, miterLimit);
-    OUTPUT:
-        RETVAL
-
 %}
 };
diff --git a/xs/xsp/PolylineCollection.xsp b/xs/xsp/PolylineCollection.xsp
deleted file mode 100644
index d8bb41b49..000000000
--- a/xs/xsp/PolylineCollection.xsp
+++ /dev/null
@@ -1,81 +0,0 @@
-%module{Slic3r::XS};
-
-%{
-#include <xsinit.h>
-
-#include "libslic3r.h"
-#include "Polyline.hpp"
-#include "ShortestPath.hpp"
-
-%}
-
-%name{Slic3r::Polyline::Collection} class PolylineCollection {
-    ~PolylineCollection();
-    Clone<PolylineCollection> clone()
-        %code{% RETVAL = THIS; %};
-    void clear()
-        %code{% THIS->polylines.clear(); %};
-    PolylineCollection* chained_path(bool no_reverse)
-        %code{%
-            RETVAL = new PolylineCollection();
-            RETVAL->polylines = chain_polylines(THIS->polylines, &THIS->polylines.front().first_point());
-        %};
-    PolylineCollection* chained_path_from(Point* start_near, bool no_reverse)
-        %code{%
-            RETVAL = new PolylineCollection();
-            RETVAL->polylines = chain_polylines(THIS->polylines, start_near);
-        %};
-    int count()
-        %code{% RETVAL = THIS->polylines.size(); %};
-%{
-
-PolylineCollection*
-PolylineCollection::new(...)
-    CODE:
-        RETVAL = new PolylineCollection ();
-        // ST(0) is class name, others are Polylines
-        RETVAL->polylines.resize(items-1);
-        for (unsigned int i = 1; i < items; i++) {
-            // Note: a COPY of the input is stored
-            from_SV_check(ST(i), &RETVAL->polylines[i-1]);
-        }
-    OUTPUT:
-        RETVAL
-
-SV*
-PolylineCollection::arrayref()
-    CODE:
-        AV* av = newAV();
-        av_fill(av, THIS->polylines.size()-1);
-        int i = 0;
-        for (Polylines::iterator it = THIS->polylines.begin(); it != THIS->polylines.end(); ++it) {
-            av_store(av, i++, perl_to_SV_ref(*it));
-        }
-        RETVAL = newRV_noinc((SV*)av);
-    OUTPUT:
-        RETVAL
-
-SV*
-PolylineCollection::pp()
-    CODE:
-        AV* av = newAV();
-        av_fill(av, THIS->polylines.size()-1);
-        int i = 0;
-        for (Polylines::iterator it = THIS->polylines.begin(); it != THIS->polylines.end(); ++it) {
-            av_store(av, i++, to_SV_pureperl(&*it));
-        }
-        RETVAL = newRV_noinc((SV*)av);
-    OUTPUT:
-        RETVAL
-
-void
-PolylineCollection::append(...)
-    CODE:
-        for (unsigned int i = 1; i < items; i++) {
-            Polyline polyline;
-            from_SV_check(ST(i), &polyline);
-            THIS->polylines.push_back(polyline);
-        }
-
-%}
-};
diff --git a/xs/xsp/Print.xsp b/xs/xsp/Print.xsp
index bffdd933f..97cbdafe3 100644
--- a/xs/xsp/Print.xsp
+++ b/xs/xsp/Print.xsp
@@ -3,27 +3,6 @@
 %{
 #include <xsinit.h>
 #include "libslic3r/Print.hpp"
-#include "libslic3r/PlaceholderParser.hpp"
-%}
-
-%package{Slic3r::Print::State};
-%{
-
-IV
-_constant()
-  ALIAS:
-    STEP_SLICE              = posSlice
-    STEP_PERIMETERS         = posPerimeters
-    STEP_PREPARE_INFILL     = posPrepareInfill
-    STEP_INFILL             = posInfill
-    STEP_SUPPORTMATERIAL    = posSupportMaterial
-    STEP_SKIRTBRIM          = psSkirtBrim
-    STEP_WIPE_TOWER         = psWipeTower
-  PROTOTYPE:
-  CODE:
-    RETVAL = ix;
-  OUTPUT: RETVAL
-
 %}
 
 %name{Slic3r::Print::Region} class PrintRegion {
@@ -45,12 +24,6 @@ _constant()
     size_t layer_count();
     Ref<Layer> get_layer(int idx);
 
-    size_t support_layer_count();
-    Ref<SupportLayer> get_support_layer(int idx);
-
-    bool step_done(PrintObjectStep step)
-        %code%{ RETVAL = THIS->is_step_done(step); %};
-
     void slice();
 };
 
@@ -62,16 +35,10 @@ _constant()
         %code%{ RETVAL = const_cast<Model*>(&THIS->model()); %};
     Ref<StaticPrintConfig> config()
         %code%{ RETVAL = const_cast<GCodeConfig*>(static_cast<const GCodeConfig*>(&THIS->config())); %};
-    Ref<PlaceholderParser> placeholder_parser()
-        %code%{ RETVAL = const_cast<PlaceholderParser*>(&THIS->placeholder_parser()); %};
     Ref<ExtrusionEntityCollection> skirt()
         %code%{ RETVAL = const_cast<ExtrusionEntityCollection*>(&THIS->skirt()); %};
     Ref<ExtrusionEntityCollection> brim()
         %code%{ RETVAL = const_cast<ExtrusionEntityCollection*>(&THIS->brim()); %};
-//    std::string estimated_normal_print_time()
-//        %code%{ RETVAL = THIS->print_statistics().estimated_normal_print_time; %};
-//    std::string estimated_silent_print_time()
-//        %code%{ RETVAL = THIS->print_statistics().estimated_silent_print_time; %};
     double total_used_filament()
         %code%{ RETVAL = THIS->print_statistics().total_used_filament; %};
     double total_extruded_volume()
@@ -96,25 +63,6 @@ _constant()
     PrintRegionPtrs* regions()
         %code%{ RETVAL = const_cast<PrintRegionPtrs*>(&THIS->print_regions_mutable()); %};
     
-    bool step_done(PrintStep step)
-        %code%{ RETVAL = THIS->is_step_done(step); %};
-    bool object_step_done(PrintObjectStep step)
-        %code%{ RETVAL = THIS->is_step_done(step); %};
-    
-    SV* filament_stats()
-        %code%{
-            HV* hv = newHV();
-            for (std::map<size_t,double>::const_iterator it = THIS->print_statistics().filament_stats.begin(); it != THIS->print_statistics().filament_stats.end(); ++it) {
-                // stringify extruder_id
-                std::ostringstream ss;
-                ss << it->first;
-                std::string str = ss.str();
-                
-                (void)hv_store( hv, str.c_str(), str.length(), newSViv(it->second), 0 );
-                RETVAL = newRV_noinc((SV*)hv);
-            }
-        %};
-    bool has_support_material() const;
     void auto_assign_extruders(ModelObject* model_object);
     std::string output_filepath(std::string path = "")
         %code%{
@@ -138,7 +86,6 @@ _constant()
                 mat.second->config.touch();
             RETVAL = THIS->apply(*model, *config);
         %};
-    bool has_infinite_skirt();
     std::vector<unsigned int> extruders() const;
     int validate() %code%{ 
             std::string err = THIS->validate(); 
@@ -147,10 +94,7 @@ _constant()
             RETVAL = 1;
         %};
 
-    void set_callback_event(int evt) %code%{
-        %};
     void set_status_silent();
-    void set_status(int percent, const char *message);
 
     void process() %code%{
             try {
diff --git a/xs/xsp/Surface.xsp b/xs/xsp/Surface.xsp
index 8804b851b..3fffea9ab 100644
--- a/xs/xsp/Surface.xsp
+++ b/xs/xsp/Surface.xsp
@@ -3,7 +3,6 @@
 %{
 #include <xsinit.h>
 #include "libslic3r/Surface.hpp"
-#include "libslic3r/ClipperUtils.hpp"
 %}
 
 %name{Slic3r::Surface} class Surface {
diff --git a/xs/xsp/TriangleMesh.xsp b/xs/xsp/TriangleMesh.xsp
index a9dbe654d..91b3b40a1 100644
--- a/xs/xsp/TriangleMesh.xsp
+++ b/xs/xsp/TriangleMesh.xsp
@@ -62,22 +62,6 @@ TriangleMesh::ReadFromPerl(vertices, facets)
         }
         *THIS = TriangleMesh(std::move(out_vertices), std::move(out_indices));
 
-SV*
-TriangleMesh::stats()
-    CODE:
-        HV* hv = newHV();
-        (void)hv_stores( hv, "number_of_facets",    newSViv(THIS->facets_count()) );
-        (void)hv_stores( hv, "number_of_parts",     newSViv(THIS->stats().number_of_parts) );
-        (void)hv_stores( hv, "volume",              newSVnv(THIS->stats().volume) );
-        (void)hv_stores( hv, "degenerate_facets",   newSViv(THIS->stats().repaired_errors.degenerate_facets) );
-        (void)hv_stores( hv, "edges_fixed",         newSViv(THIS->stats().repaired_errors.edges_fixed) );
-        (void)hv_stores( hv, "facets_removed",      newSViv(THIS->stats().repaired_errors.facets_removed) );
-        (void)hv_stores( hv, "facets_reversed",     newSViv(THIS->stats().repaired_errors.facets_reversed) );
-        (void)hv_stores( hv, "backwards_edges",     newSViv(THIS->stats().repaired_errors.backwards_edges) );
-        RETVAL = (SV*)newRV_noinc((SV*)hv);
-    OUTPUT:
-        RETVAL
-
 SV*
 TriangleMesh::vertices()
     CODE:
@@ -128,78 +112,5 @@ TriangleMesh::size()
     OUTPUT:
         RETVAL
 
-SV*
-TriangleMesh::slice(z)
-    std::vector<double> z
-    CODE:
-        // convert doubles to floats
-        std::vector<float> z_f = cast<float>(z);
-        
-        std::vector<ExPolygons> layers = slice_mesh_ex(THIS->its, z_f, 0.049f);
-        
-        AV* layers_av = newAV();
-        size_t len = layers.size();
-        if (len > 0) av_extend(layers_av, len-1);
-        for (unsigned int i = 0; i < layers.size(); i++) {
-            AV* expolygons_av = newAV();
-            len = layers[i].size();
-            if (len > 0) av_extend(expolygons_av, len-1);
-            unsigned int j = 0;
-            for (ExPolygons::iterator it = layers[i].begin(); it != layers[i].end(); ++it) {
-                av_store(expolygons_av, j++, perl_to_SV_clone_ref(*it));
-            }
-            av_store(layers_av, i, newRV_noinc((SV*)expolygons_av));
-        }
-        RETVAL = (SV*)newRV_noinc((SV*)layers_av);
-    OUTPUT:
-        RETVAL
-
-void
-TriangleMesh::cut(z, upper_mesh, lower_mesh)
-    float           z;
-    TriangleMesh*   upper_mesh;
-    TriangleMesh*   lower_mesh;
-    CODE:
-        indexed_triangle_set upper, lower;
-        cut_mesh(THIS->its, z, upper_mesh ? &upper : nullptr, lower_mesh ? &lower : nullptr);
-        if (upper_mesh)
-            *upper_mesh = TriangleMesh(upper);
-        if (lower_mesh)
-            *lower_mesh = TriangleMesh(lower);
-
-std::vector<double>
-TriangleMesh::bb3()
-    CODE:
-        RETVAL.push_back(THIS->stats().min(0));
-        RETVAL.push_back(THIS->stats().min(1));
-        RETVAL.push_back(THIS->stats().max(0));
-        RETVAL.push_back(THIS->stats().max(1));
-        RETVAL.push_back(THIS->stats().min(2));
-        RETVAL.push_back(THIS->stats().max(2));
-    OUTPUT:
-        RETVAL
-
-
-Clone<TriangleMesh>
-cube(double x, double y, double z) 
-    CODE:
-        RETVAL = make_cube(x,y,z);
-    OUTPUT:
-        RETVAL
-
-Clone<TriangleMesh> 
-cylinder(double r, double h) 
-    CODE:
-        RETVAL = make_cylinder(r, h);
-    OUTPUT:
-        RETVAL
-
-Clone<TriangleMesh>
-sphere(double rho)
-    CODE:
-        RETVAL = make_sphere(rho);
-    OUTPUT:
-        RETVAL
-
 %}
 };
diff --git a/xs/xsp/XS.xsp b/xs/xsp/XS.xsp
index 68ea282bc..66a35366b 100644
--- a/xs/xsp/XS.xsp
+++ b/xs/xsp/XS.xsp
@@ -35,129 +35,4 @@ set_logging_level(level)
     CODE:
         Slic3r::set_logging_level(level);
 
-void
-trace(level, message)
-    unsigned int level;
-    char        *message;
-    CODE:
-        Slic3r::trace(level, message);
-
-void
-disable_multi_threading()
-    CODE:
-        Slic3r::disable_multi_threading();
-
-void
-set_var_dir(dir)
-    char  *dir;
-    CODE:
-        Slic3r::set_var_dir(dir);
-
-void
-set_local_dir(dir)
-    char  *dir;
-    CODE:
-        Slic3r::set_local_dir(dir);
-
-char*
-var_dir()
-    CODE:
-        RETVAL = const_cast<char*>(Slic3r::var_dir().c_str());
-    OUTPUT: RETVAL
-
-void
-set_resources_dir(dir)
-    char  *dir;
-    CODE:
-        Slic3r::set_resources_dir(dir);
-
-char*
-resources_dir()
-    CODE:
-        RETVAL = const_cast<char*>(Slic3r::resources_dir().c_str());
-    OUTPUT: RETVAL
-
-std::string
-var(file_name)
-    const char *file_name;
-    CODE:
-        RETVAL = Slic3r::var(file_name);
-    OUTPUT: RETVAL
-
-void
-set_data_dir(dir)
-    char  *dir;
-    CODE:
-        Slic3r::set_data_dir(dir);
-
-char*
-data_dir()
-    CODE:
-        RETVAL = const_cast<char*>(Slic3r::data_dir().c_str());
-    OUTPUT: RETVAL
-
-local_encoded_string
-encode_path(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::encode_path(src);
-    OUTPUT: RETVAL
-
-std::string
-decode_path(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::decode_path(src);
-    OUTPUT: RETVAL
-
-std::string
-normalize_utf8_nfc(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::normalize_utf8_nfc(src);
-    OUTPUT: RETVAL
-
-std::string
-path_to_filename(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::PerlUtils::path_to_filename(src);
-    OUTPUT: RETVAL
-
-local_encoded_string
-path_to_filename_raw(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::PerlUtils::path_to_filename(src);
-    OUTPUT: RETVAL
-
-std::string
-path_to_stem(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::PerlUtils::path_to_stem(src);
-    OUTPUT: RETVAL
-
-std::string
-path_to_extension(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::PerlUtils::path_to_extension(src);
-    OUTPUT: RETVAL
-
-std::string
-path_to_parent_path(src)
-    const char *src;
-    CODE:
-        RETVAL = Slic3r::PerlUtils::path_to_parent_path(src);
-    OUTPUT: RETVAL
-
-void
-xspp_test_croak_hangs_on_strawberry()
-    CODE:
-    	try {
-    		throw 1;
-    	} catch (...) {
-    		croak("xspp_test_croak_hangs_on_strawberry: exception catched\n");
-    	}
-%}
\ No newline at end of file
+%}
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index a660041bc..131f82e79 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -1,7 +1,6 @@
 coordf_t T_NV
 
 std::string                     T_STD_STRING
-local_encoded_string     		T_STD_STRING_LOCAL_ENCODING
 t_config_option_key             T_STD_STRING
 t_model_material_id             T_STD_STRING
 
@@ -15,9 +14,6 @@ std::vector<unsigned int>	    T_STD_VECTOR_UINT
 
 std::vector<double>	            T_STD_VECTOR_DOUBLE
 
-t_layer_height_ranges           T_LAYER_HEIGHT_RANGES
-
-
 BoundingBox*               O_OBJECT_SLIC3R
 Ref<BoundingBox>           O_OBJECT_SLIC3R_T
 Clone<BoundingBox>         O_OBJECT_SLIC3R_T
@@ -52,8 +48,6 @@ Ref<PrintConfig>           O_OBJECT_SLIC3R_T
 FullPrintConfig*           O_OBJECT_SLIC3R
 Ref<FullPrintConfig>       O_OBJECT_SLIC3R_T
 
-ZTable*                    O_OBJECT
-
 TriangleMesh*              O_OBJECT_SLIC3R
 Ref<TriangleMesh>          O_OBJECT_SLIC3R_T
 Clone<TriangleMesh>        O_OBJECT_SLIC3R_T
@@ -86,10 +80,6 @@ Polyline*                  O_OBJECT_SLIC3R
 Ref<Polyline>              O_OBJECT_SLIC3R_T
 Clone<Polyline>            O_OBJECT_SLIC3R_T
 
-PolylineCollection*        O_OBJECT_SLIC3R
-Ref<PolylineCollection>    O_OBJECT_SLIC3R_T
-Clone<PolylineCollection>  O_OBJECT_SLIC3R_T
-
 Polygon*                   O_OBJECT_SLIC3R
 Ref<Polygon>               O_OBJECT_SLIC3R_T
 Clone<Polygon>             O_OBJECT_SLIC3R_T
@@ -122,9 +112,6 @@ Flow*                      O_OBJECT_SLIC3R
 Ref<Flow>                  O_OBJECT_SLIC3R_T
 Clone<Flow>                O_OBJECT_SLIC3R_T
 
-PrintState*                O_OBJECT_SLIC3R
-Ref<PrintState>            O_OBJECT_SLIC3R_T
-
 Surface*                   O_OBJECT_SLIC3R
 Ref<Surface>               O_OBJECT_SLIC3R_T
 Clone<Surface>             O_OBJECT_SLIC3R_T
@@ -168,13 +155,6 @@ Ref<LayerRegion>           O_OBJECT_SLIC3R_T
 Layer*                     O_OBJECT_SLIC3R
 Ref<Layer>                 O_OBJECT_SLIC3R_T
 
-SupportLayer*              O_OBJECT_SLIC3R
-Ref<SupportLayer>          O_OBJECT_SLIC3R_T
-
-PlaceholderParser*         O_OBJECT_SLIC3R
-Ref<PlaceholderParser>     O_OBJECT_SLIC3R_T
-Clone<PlaceholderParser>   O_OBJECT_SLIC3R_T
-
 CoolingBuffer*             O_OBJECT_SLIC3R
 Ref<CoolingBuffer>         O_OBJECT_SLIC3R_T
 Clone<CoolingBuffer>       O_OBJECT_SLIC3R_T
@@ -187,21 +167,10 @@ BridgeDetector*            O_OBJECT_SLIC3R
 Ref<BridgeDetector>        O_OBJECT_SLIC3R_T
 Clone<BridgeDetector>      O_OBJECT_SLIC3R_T
 
-PerimeterGenerator*         O_OBJECT_SLIC3R
-Ref<PerimeterGenerator>     O_OBJECT_SLIC3R_T
-Clone<PerimeterGenerator>   O_OBJECT_SLIC3R_T
-
-PrintObjectSupportMaterial*       O_OBJECT_SLIC3R
-Ref<PrintObjectSupportMaterial>   O_OBJECT_SLIC3R_T
-Clone<PrintObjectSupportMaterial> O_OBJECT_SLIC3R_T
-
 Axis                  T_UV
 ExtrusionLoopRole     T_UV
 ExtrusionRole     T_UV
-ExtrusionSimulationType T_UV
 FlowRole     T_UV
-PrintStep     T_UV
-PrintObjectStep     T_UV
 SurfaceType     T_UV
 Slic3r::ClipperLib::JoinType		T_UV
 Slic3r::ClipperLib::PolyFillType		T_UV
@@ -226,7 +195,6 @@ ModelInstancePtrs*  T_PTR_ARRAYREF_PTR
 PrintRegionPtrs*    T_PTR_ARRAYREF_PTR
 PrintObjectPtrs*    T_PTR_ARRAYREF_PTR
 LayerPtrs*          T_PTR_ARRAYREF_PTR
-SupportLayerPtrs*   T_PTR_ARRAYREF_PTR
 
 # we return these types whenever we want the items to be returned
 # by reference and not marked ::Ref because they're newly allocated
@@ -244,14 +212,6 @@ T_STD_STRING
       $var = std::string(c, len);
     }
 
-INPUT
-T_STD_STRING_LOCAL_ENCODING
-    {
-      size_t len;
-      const char * c = SvPV($arg, len);
-      $var = std::string(c, len);
-    }
-
 T_STD_VECTOR_STD_STRING
 	if (SvROK($arg) && SvTYPE(SvRV($arg))==SVt_PVAV) {
 	  AV* av = (AV*)SvRV($arg);
@@ -359,61 +319,11 @@ T_ARRAYREF
 	             ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
 	             \"$var\");
 
-T_LAYER_HEIGHT_RANGES
-    {
-        if (!SvROK($arg) || SvTYPE(SvRV($arg)) != SVt_PVAV) {
-            Perl_croak(aTHX_ \"%s: %s is not an array reference\",
-                     ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
-                     \"$var\");
-        }
-
-        AV* av = (AV*)SvRV($arg);
-        const unsigned int len = av_len(av)+1;
-        t_layer_height_ranges tmp_ranges;
-        for (unsigned int i = 0; i < len; i++) {
-            SV* elem = *av_fetch(av, i, 0);
-            if (!SvROK(elem) || SvTYPE(SvRV(elem)) != SVt_PVAV) {
-                Perl_croak(
-                    aTHX_ \"%s: %s contains something that is not an array reference\",
-                        ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
-                        \"$var\");
-            }
-
-            AV* elemAV = (AV*)SvRV(elem);
-            if (av_len(elemAV) + 1 != 3) {
-                Perl_croak(
-                    aTHX_ \"%s: %s contains an array that isn't 3 elements long\",
-                        ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]},
-                        \"$var\");
-            }
-
-            coordf_t vals[3];
-            for (unsigned int j = 0; j < 3; ++j) {
-                SV *elem_elem = *av_fetch(elemAV, j, 0);
-                if (!looks_like_number(elem_elem)) {
-                    Perl_croak(
-                        aTHX_ \"%s: layer ranges and heights must be numbers\",
-                            ${$ALIAS?\q[GvNAME(CvGV(cv))]:\qq[\"$pname\"]});
-                }
-
-                vals[j] = SvNV(elem_elem);
-            }
-
-            tmp_ranges[t_layer_height_range(vals[0], vals[1])] = vals[2];
-        }
-
-        $var = tmp_ranges;
-    }
-
-
 OUTPUT
 
 T_STD_STRING
     $arg = newSVpvn_utf8( $var.c_str(), $var.length(), true );
 
-T_STD_STRING_LOCAL_ENCODING
-    $arg = newSVpvn( $var.c_str(), $var.length() );
-
 T_STD_VECTOR_STD_STRING
 	AV* av = newAV();
 	$arg = newRV_noinc((SV*)av);
@@ -517,26 +427,3 @@ T_PTR_ARRAYREF
         av_store(av, i++, to_SV(*it));
 	}
 
-T_LAYER_HEIGHT_RANGES
-    AV* av = newAV();
-    $arg = newRV_noinc((SV*)av);
-    sv_2mortal($arg);
-	const unsigned int len = $var.size();
-	if (len > 0) av_extend(av, len-1);
-    // map is sorted, so we can just copy it in order
-    int i = 0;
-    for (${type}::iterator it = $var.begin(); it != $var.end(); ++it) {
-        const coordf_t range_values[] = {
-                it->first.first,    // key's first = minz
-                it->first.second,   // key's second = maxz
-                it->second,         // value = height
-            };
-
-        AV *rangeAV = newAV();
-        av_extend(rangeAV, 2);
-        for (int j = 0; j < 3; ++j) {
-            av_store(rangeAV, j, newSVnv(range_values[j]));
-        }
-
-        av_store(av, i++, (SV*)newRV_noinc((SV*)rangeAV));
-    }
diff --git a/xs/xsp/typemap.xspt b/xs/xsp/typemap.xspt
index cc7109445..b59f4b74c 100644
--- a/xs/xsp/typemap.xspt
+++ b/xs/xsp/typemap.xspt
@@ -12,7 +12,6 @@
 %typemap{std::vector<unsigned int>};
 %typemap{std::vector<unsigned int>*};
 %typemap{std::vector<std::string>};
-%typemap{t_layer_height_ranges};
 %typemap{void*};
 %typemap{SV*};
 %typemap{AV*};
@@ -88,18 +87,12 @@
 %typemap{TriangleMesh*};
 %typemap{Ref<TriangleMesh>}{simple};
 %typemap{Clone<TriangleMesh>}{simple};
-%typemap{PolylineCollection*};
-%typemap{Ref<PolylineCollection>}{simple};
-%typemap{Clone<PolylineCollection>}{simple};
 %typemap{BridgeDetector*};
 %typemap{Ref<BridgeDetector>}{simple};
 %typemap{Clone<BridgeDetector>}{simple};
 %typemap{SurfaceCollection*};
 %typemap{Ref<SurfaceCollection>}{simple};
 %typemap{Clone<SurfaceCollection>}{simple};
-%typemap{PerimeterGenerator*};
-%typemap{Ref<PerimeterGenerator>}{simple};
-%typemap{Clone<PerimeterGenerator>}{simple};
 
 %typemap{Surface*};
 %typemap{Ref<Surface>}{simple};
@@ -124,17 +117,6 @@
 %typemap{Layer*};
 %typemap{Ref<Layer>}{simple};
 
-%typemap{SupportLayer*};
-%typemap{Ref<SupportLayer>}{simple};
-
-%typemap{PrintObjectSupportMaterial*};
-%typemap{Ref<PrintObjectSupportMaterial>}{simple};
-%typemap{Clone<PrintObjectSupportMaterial>}{simple};
-
-%typemap{PlaceholderParser*};
-%typemap{Ref<PlaceholderParser>}{simple};
-%typemap{Clone<PlaceholderParser>}{simple};
-
 %typemap{CoolingBuffer*};
 %typemap{Ref<CoolingBuffer>}{simple};
 %typemap{Clone<CoolingBuffer>}{simple};
@@ -181,13 +163,10 @@
 %typemap{ModelInstancePtrs*};
 %typemap{Ref<ModelInstancePtrs>}{simple};
 %typemap{Clone<ModelInstancePtrs>}{simple};
-%typemap{PresetHints*};
-%typemap{Ref<PresetHints>}{simple};
 
 %typemap{PrintRegionPtrs*};
 %typemap{PrintObjectPtrs*};
 %typemap{LayerPtrs*};
-%typemap{SupportLayerPtrs*};
 
 %typemap{Axis}{parsed}{
   %cpp_type{Axis};
@@ -213,27 +192,9 @@
     $CVar = (ExtrusionRole)SvUV($PerlVar);
   %};
 };
-%typemap{ExtrusionSimulationType}{parsed}{
-  %cpp_type{ExtrusionSimulationType};
-  %precall_code{%
-    $CVar = (ExtrusionSimulationType)SvUV($PerlVar);
-  %};
-};
 %typemap{FlowRole}{parsed}{
   %cpp_type{FlowRole};
   %precall_code{%
     $CVar = (FlowRole)SvUV($PerlVar);
   %};
 };
-%typemap{PrintStep}{parsed}{
-  %cpp_type{PrintStep};
-  %precall_code{%
-    $CVar = (PrintStep)SvUV($PerlVar);
-  %};
-};
-%typemap{PrintObjectStep}{parsed}{
-  %cpp_type{PrintObjectStep};
-  %precall_code{%
-    $CVar = (PrintObjectStep)SvUV($PerlVar);
-  %};
-};