From 8e0d458d1d7e646e75d34d7fcb8c19d2215143e8 Mon Sep 17 00:00:00 2001
From: Vicious-one <valve.via@gmail.com>
Date: Wed, 30 Sep 2015 16:22:49 +0300
Subject: [PATCH 01/13] Fix for #3069

---
 xs/src/libslic3r/GCode.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xs/src/libslic3r/GCode.cpp b/xs/src/libslic3r/GCode.cpp
index 51093667af..f1fe42817a 100644
--- a/xs/src/libslic3r/GCode.cpp
+++ b/xs/src/libslic3r/GCode.cpp
@@ -2,6 +2,7 @@
 #include "ExtrusionEntity.hpp"
 #include <algorithm>
 #include <cstdlib>
+#include <math.h>
 
 namespace Slic3r {
 
@@ -400,7 +401,7 @@ GCode::extrude(ExtrusionLoop loop, std::string description, double speed)
             Polygon polygon = loop.polygon();
             Point centroid = polygon.centroid();
             last_pos = Point(polygon.bounding_box().max.x, centroid.y);
-            last_pos.rotate(rand() % 2*PI, centroid);
+            last_pos.rotate(fmod((float)rand()/16.0, 2.0*PI), centroid);
         }
         loop.split_at(last_pos);
     }

From 5f8eea9adf6744bd3c4d7e59cc665f65602df857 Mon Sep 17 00:00:00 2001
From: Chow Loong Jin <hyperair@debian.org>
Date: Sun, 6 Mar 2016 17:44:39 +0800
Subject: [PATCH 02/13] Don't use equality comparisons for floats

This fixes an issue where F0 moves arise from 0-width (or 0 layer
height?) support material segments when using autospeed.

Fixes: #3261
---
 lib/Slic3r/Print/GCode.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/Slic3r/Print/GCode.pm b/lib/Slic3r/Print/GCode.pm
index e3022fef05..b7a48870a4 100644
--- a/lib/Slic3r/Print/GCode.pm
+++ b/lib/Slic3r/Print/GCode.pm
@@ -75,7 +75,8 @@ sub BUILD {
                     }
                 }
             }
-            @mm3_per_mm = grep $_ != 0, @mm3_per_mm;
+            # filter out 0-width segments
+            @mm3_per_mm = grep $_ > 0.000001, @mm3_per_mm;
             if (@mm3_per_mm) {
                 my $min_mm3_per_mm = min(@mm3_per_mm);
                 # In order to honor max_print_speed we need to find a target volumetric

From 209b919fe6e90cd6ad06f09096cdf030de09b73c Mon Sep 17 00:00:00 2001
From: Chow Loong Jin <hyperair@debian.org>
Date: Thu, 12 May 2016 23:31:26 +0800
Subject: [PATCH 03/13] Fix cooling not working if !gcode_comments

The cooling markers were being passed into GCodeWriter::set_speed() as a
comment which were being ignored if gcode_comments was false.

Fixes: #3325
---
 xs/src/libslic3r/GCode.cpp       | 4 ++--
 xs/src/libslic3r/GCodeWriter.cpp | 4 +++-
 xs/src/libslic3r/GCodeWriter.hpp | 2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/xs/src/libslic3r/GCode.cpp b/xs/src/libslic3r/GCode.cpp
index 88020246b3..066d94f2d2 100644
--- a/xs/src/libslic3r/GCode.cpp
+++ b/xs/src/libslic3r/GCode.cpp
@@ -177,7 +177,7 @@ Wipe::wipe(GCode &gcodegen, bool toolchange)
             /*  Reduce retraction length a bit to avoid effective retraction speed to be greater than the configured one
                 due to rounding (TODO: test and/or better math for this)  */
             double dE = length * (segment_length / wipe_dist) * 0.95;
-            gcode += gcodegen.writer.set_speed(wipe_speed*60, gcodegen.enable_cooling_markers ? ";_WIPE" : "");
+            gcode += gcodegen.writer.set_speed(wipe_speed*60, "", gcodegen.enable_cooling_markers ? ";_WIPE" : "");
             gcode += gcodegen.writer.extrude_to_xy(
                 gcodegen.point_to_gcode(line->b),
                 -dE,
@@ -562,7 +562,7 @@ GCode::_extrude(ExtrusionPath path, std::string description, double speed)
     // extrude arc or line
     if (path.is_bridge() && this->enable_cooling_markers)
         gcode += ";_BRIDGE_FAN_START\n";
-    gcode += this->writer.set_speed(F, this->enable_cooling_markers ? ";_EXTRUDE_SET_SPEED" : "");
+    gcode += this->writer.set_speed(F, "", this->enable_cooling_markers ? ";_EXTRUDE_SET_SPEED" : "");
     double path_length = 0;
     {
         std::string comment = this->config.gcode_comments ? description : "";
diff --git a/xs/src/libslic3r/GCodeWriter.cpp b/xs/src/libslic3r/GCodeWriter.cpp
index d932fd83f6..bb52218776 100644
--- a/xs/src/libslic3r/GCodeWriter.cpp
+++ b/xs/src/libslic3r/GCodeWriter.cpp
@@ -273,11 +273,13 @@ GCodeWriter::toolchange(unsigned int extruder_id)
 }
 
 std::string
-GCodeWriter::set_speed(double F, const std::string &comment) const
+GCodeWriter::set_speed(double F, const std::string &comment,
+                       const std::string &cooling_marker) const
 {
     std::ostringstream gcode;
     gcode << "G1 F" << F;
     COMMENT(comment);
+    gcode << cooling_marker;
     gcode << "\n";
     return gcode.str();
 }
diff --git a/xs/src/libslic3r/GCodeWriter.hpp b/xs/src/libslic3r/GCodeWriter.hpp
index 21ed8d2411..72d54215b3 100644
--- a/xs/src/libslic3r/GCodeWriter.hpp
+++ b/xs/src/libslic3r/GCodeWriter.hpp
@@ -34,7 +34,7 @@ class GCodeWriter {
     bool need_toolchange(unsigned int extruder_id) const;
     std::string set_extruder(unsigned int extruder_id);
     std::string toolchange(unsigned int extruder_id);
-    std::string set_speed(double F, const std::string &comment = std::string()) const;
+    std::string set_speed(double F, const std::string &comment = std::string(), const std::string &cooling_marker = std::string()) const;
     std::string travel_to_xy(const Pointf &point, const std::string &comment = std::string());
     std::string travel_to_xyz(const Pointf3 &point, const std::string &comment = std::string());
     std::string travel_to_z(double z, const std::string &comment = std::string());

From d8be976356820996f6249228c21c9ace0075a9e1 Mon Sep 17 00:00:00 2001
From: bubnikv <bubnikv@gmail.com>
Date: Mon, 16 May 2016 23:40:24 +0200
Subject: [PATCH 04/13] The "controller" tab and the settings of the USB/serial
 connection was made configurable. Now one may hide the "controller" tab and
 the USB/serial connection configuration from the preferences. This is useful
 for someone, who never connects his printer to the computer by a cable.

---
 lib/Slic3r/GUI.pm             | 13 +++++++++++--
 lib/Slic3r/GUI/MainFrame.pm   | 22 ++++++++++++++++------
 lib/Slic3r/GUI/Preferences.pm |  9 ++++++++-
 lib/Slic3r/GUI/Tab.pm         | 19 ++++++++++++-------
 slic3r.pl                     | 10 ++++++----
 5 files changed, 53 insertions(+), 20 deletions(-)

diff --git a/lib/Slic3r/GUI.pm b/lib/Slic3r/GUI.pm
index 077b5625b8..7f4a028a5f 100644
--- a/lib/Slic3r/GUI.pm
+++ b/lib/Slic3r/GUI.pm
@@ -53,6 +53,8 @@ use constant FILE_WILDCARDS => {
 use constant MODEL_WILDCARD => join '|', @{&FILE_WILDCARDS}{qw(known stl obj amf)};
 
 our $datadir;
+# If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
+our $no_controller;
 our $no_plater;
 our $mode;
 our $autosave;
@@ -64,6 +66,9 @@ our $Settings = {
         version_check => 1,
         autocenter => 1,
         background_processing => 1,
+        # If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
+        # By default, Prusa has the controller hidden.
+        no_controller => 1,
     },
 };
 
@@ -115,6 +120,8 @@ sub OnInit {
         $Settings->{_}{mode} ||= 'expert';
         $Settings->{_}{autocenter} //= 1;
         $Settings->{_}{background_processing} //= 1;
+        # If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
+        $Settings->{_}{no_controller} //= 1;
     }
     $Settings->{_}{version} = $Slic3r::VERSION;
     $self->save_settings;
@@ -122,8 +129,10 @@ sub OnInit {
     # application frame
     Wx::Image::AddHandler(Wx::PNGHandler->new);
     $self->{mainframe} = my $frame = Slic3r::GUI::MainFrame->new(
-        mode        => $mode // $Settings->{_}{mode},
-        no_plater   => $no_plater,
+        mode            => $mode // $Settings->{_}{mode},
+        # If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
+        no_controller   => $no_controller // $Settings->{_}{no_controller},
+        no_plater       => $no_plater,
     );
     $self->SetTopWindow($frame);
     
diff --git a/lib/Slic3r/GUI/MainFrame.pm b/lib/Slic3r/GUI/MainFrame.pm
index d2661765cc..d97ad22efc 100644
--- a/lib/Slic3r/GUI/MainFrame.pm
+++ b/lib/Slic3r/GUI/MainFrame.pm
@@ -24,6 +24,8 @@ sub new {
     # store input params
     $self->{mode} = $params{mode};
     $self->{mode} = 'expert' if $self->{mode} !~ /^(?:simple|expert)$/;
+    # If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
+    $self->{no_controller} = $params{no_controller};
     $self->{no_plater} = $params{no_plater};
     $self->{loaded} = 0;
     
@@ -96,7 +98,9 @@ sub _init_tabpanel {
     
     if (!$self->{no_plater}) {
         $panel->AddPage($self->{plater} = Slic3r::GUI::Plater->new($panel), "Plater");
-        $panel->AddPage($self->{controller} = Slic3r::GUI::Controller->new($panel), "Controller");
+        if (!$self->{no_controller}) {
+            $panel->AddPage($self->{controller} = Slic3r::GUI::Controller->new($panel), "Controller");
+        }
     }
     $self->{options_tabs} = {};
     
@@ -109,7 +113,9 @@ sub _init_tabpanel {
     my $class_prefix = $self->{mode} eq 'simple' ? "Slic3r::GUI::SimpleTab::" : "Slic3r::GUI::Tab::";
     for my $tab_name (qw(print filament printer)) {
         my $tab;
-        $tab = $self->{options_tabs}{$tab_name} = ($class_prefix . ucfirst $tab_name)->new($panel);
+        $tab = $self->{options_tabs}{$tab_name} = ($class_prefix . ucfirst $tab_name)->new(
+            $panel, 
+            no_controller => $self->{no_controller});
         $tab->on_value_change(sub {
             my ($opt_key, $value) = @_;
             
@@ -136,7 +142,9 @@ sub _init_tabpanel {
             if ($self->{plater}) {
                 $self->{plater}->update_presets($tab_name, @_);
                 $self->{plater}->on_config_change($tab->config);
-                $self->{controller}->update_presets($tab_name, @_);
+                if ($self->{controller}) {
+                    $self->{controller}->update_presets($tab_name, @_);
+                }
             }
         });
         $tab->load_presets;
@@ -246,9 +254,11 @@ sub _init_menubar {
             $self->_append_menu_item($windowMenu, "Select &Plater Tab\tCtrl+1", 'Show the plater', sub {
                 $self->select_tab(0);
             }, undef, 'application_view_tile.png');
-            $self->_append_menu_item($windowMenu, "Select &Controller Tab\tCtrl+T", 'Show the printer controller', sub {
-                $self->select_tab(1);
-            }, undef, 'printer_empty.png');
+            if (!$self->{no_controller}) {
+                $self->_append_menu_item($windowMenu, "Select &Controller Tab\tCtrl+T", 'Show the printer controller', sub {
+                    $self->select_tab(1);
+                }, undef, 'printer_empty.png');
+            }
             $windowMenu->AppendSeparator();
             $tab_offset += 2;
         }
diff --git a/lib/Slic3r/GUI/Preferences.pm b/lib/Slic3r/GUI/Preferences.pm
index 74846cfc96..ed210d2293 100644
--- a/lib/Slic3r/GUI/Preferences.pm
+++ b/lib/Slic3r/GUI/Preferences.pm
@@ -58,6 +58,13 @@ sub new {
         default     => $Slic3r::GUI::Settings->{_}{background_processing},
         readonly    => !$Slic3r::have_threads,
     ));
+    $optgroup->append_single_option_line(Slic3r::GUI::OptionsGroup::Option->new(
+        opt_id      => 'no_controller',
+        type        => 'bool',
+        label       => 'Disable USB/serial connection',
+        tooltip     => 'Disable communication with the printer over a serial / USB cable. This simplifies the user interface in case the printer is never attached to the computer.',
+        default     => $Slic3r::GUI::Settings->{_}{no_controller},
+    ));
     
     my $sizer = Wx::BoxSizer->new(wxVERTICAL);
     $sizer->Add($optgroup->sizer, 0, wxEXPAND | wxBOTTOM | wxLEFT | wxRIGHT, 10);
@@ -75,7 +82,7 @@ sub new {
 sub _accept {
     my $self = shift;
     
-    if ($self->{values}{mode}) {
+    if ($self->{values}{mode} || defined($self->{values}{no_controller})) {
         Slic3r::GUI::warning_catcher($self)->("You need to restart Slic3r to make the changes effective.");
     }
     
diff --git a/lib/Slic3r/GUI/Tab.pm b/lib/Slic3r/GUI/Tab.pm
index 3736d1b023..9c0ee57885 100644
--- a/lib/Slic3r/GUI/Tab.pm
+++ b/lib/Slic3r/GUI/Tab.pm
@@ -107,7 +107,7 @@ sub new {
     });
     
     $self->{config} = Slic3r::Config->new;
-    $self->build;
+    $self->build(%params);
     $self->update_tree;
     $self->_update;
     if ($self->hidden_options) {
@@ -985,6 +985,7 @@ sub title { 'Printer Settings' }
 
 sub build {
     my $self = shift;
+    my (%params) = @_;
     
     $self->init_config_options(qw(
         bed_shape z_offset
@@ -1064,6 +1065,7 @@ sub build {
                 }
             });
         }
+        if (!$params{no_controller})
         {
             my $optgroup = $page->new_optgroup('USB/Serial connection');
             my $line = Slic3r::GUI::OptionsGroup::Line->new(
@@ -1239,7 +1241,7 @@ sub build {
     
     $self->{extruder_pages} = [];
     $self->_build_extruder_pages;
-    $self->_update_serial_ports;
+    $self->_update_serial_ports if (!$params{no_controller});
 }
 
 sub _update_serial_ports {
@@ -1341,11 +1343,14 @@ sub _update {
     
     my $config = $self->{config};
     
-    $self->get_field('serial_speed')->toggle($config->get('serial_port'));
-    if ($config->get('serial_speed') && $config->get('serial_port')) {
-        $self->{serial_test_btn}->Enable;
-    } else {
-        $self->{serial_test_btn}->Disable;
+    my $serial_speed = $self->get_field('serial_speed');
+    if ($serial_speed) {
+        $self->get_field('serial_speed')->toggle($config->get('serial_port'));
+        if ($config->get('serial_speed') && $config->get('serial_port')) {
+            $self->{serial_test_btn}->Enable;
+        } else {
+            $self->{serial_test_btn}->Disable;
+        }
     }
     if ($config->get('octoprint_host') && eval "use LWP::UserAgent; 1") {
         $self->{octoprint_host_test_btn}->Enable;
diff --git a/slic3r.pl b/slic3r.pl
index db3fca5fe8..cc6192641c 100755
--- a/slic3r.pl
+++ b/slic3r.pl
@@ -32,6 +32,7 @@ my %cli_options = ();
         'load=s@'               => \$opt{load},
         'autosave=s'            => \$opt{autosave},
         'ignore-nonexistent-config' => \$opt{ignore_nonexistent_config},
+        'no-controller'         => \$opt{no_controller},
         'no-plater'             => \$opt{no_plater},
         'gui-mode=s'            => \$opt{gui_mode},
         'datadir=s'             => \$opt{datadir},
@@ -99,10 +100,11 @@ my $gui;
 if ((!@ARGV || $opt{gui}) && !$opt{save} && eval "require Slic3r::GUI; 1") {
     {
         no warnings 'once';
-        $Slic3r::GUI::datadir   = Slic3r::decode_path($opt{datadir} // '');
-        $Slic3r::GUI::no_plater = $opt{no_plater};
-        $Slic3r::GUI::mode      = $opt{gui_mode};
-        $Slic3r::GUI::autosave  = $opt{autosave};
+        $Slic3r::GUI::datadir       = Slic3r::decode_path($opt{datadir} // '');
+        $Slic3r::GUI::no_controller = $opt{no_controller};
+        $Slic3r::GUI::no_plater     = $opt{no_plater};
+        $Slic3r::GUI::mode          = $opt{gui_mode};
+        $Slic3r::GUI::autosave      = $opt{autosave};
     }
     $gui = Slic3r::GUI->new;
     setlocale(LC_NUMERIC, 'C');

From 9e8022f6f62b6f4c07b5846a765128b3609e53ef Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Fri, 20 May 2016 06:24:05 +0200
Subject: [PATCH 05/13] More refactoring to medial axis and gap fill, more
 robust

---
 t/thin.t                                | 19 +++++-
 xs/src/libslic3r/ExPolygon.cpp          | 37 ++++++-----
 xs/src/libslic3r/ExPolygon.hpp          |  1 +
 xs/src/libslic3r/Geometry.cpp           | 87 +++++++++++++++----------
 xs/src/libslic3r/Geometry.hpp           |  4 +-
 xs/src/libslic3r/Line.cpp               |  6 ++
 xs/src/libslic3r/Line.hpp               |  1 +
 xs/src/libslic3r/MultiPoint.cpp         | 13 ++++
 xs/src/libslic3r/MultiPoint.hpp         |  1 +
 xs/src/libslic3r/PerimeterGenerator.cpp |  2 +-
 xs/src/libslic3r/Point.cpp              | 16 +++++
 xs/src/libslic3r/Point.hpp              |  2 +
 xs/xsp/Line.xsp                         |  2 +
 13 files changed, 133 insertions(+), 58 deletions(-)

diff --git a/t/thin.t b/t/thin.t
index 276a29e2b8..5146148025 100644
--- a/t/thin.t
+++ b/t/thin.t
@@ -1,4 +1,4 @@
-use Test::More tests => 21;
+use Test::More tests => 23;
 use strict;
 use warnings;
 
@@ -8,7 +8,7 @@ BEGIN {
 }
 
 use Slic3r;
-use List::Util qw(first sum);
+use List::Util qw(first sum none);
 use Slic3r::Geometry qw(epsilon scale unscale scaled_epsilon Y);
 use Slic3r::Test;
 
@@ -91,7 +91,20 @@ if (0) {
     is scalar(@$res), 1, 'medial axis of a narrow rectangle with an extra vertex is still a single line';
     ok unscale($res->[0]->length) >= (200-100 - (120-100)) - epsilon, 'medial axis has still a reasonable length';
     ok !(grep { abs($_ - scale 150) < scaled_epsilon } map $_->[Y], map @$_, @$res2), "extra vertices don't influence medial axis";
+}
+
+{
+    my $expolygon = Slic3r::ExPolygon->new(
+        Slic3r::Polygon->new([1185881,829367],[1421988,1578184],[1722442,2303558],[2084981,2999998],[2506843,3662186],[2984809,4285086],[3515250,4863959],[4094122,5394400],[4717018,5872368],[5379210,6294226],[6075653,6656769],[6801033,6957229],[7549842,7193328],[8316383,7363266],[9094809,7465751],[9879211,7500000],[10663611,7465750],[11442038,7363265],[12208580,7193327],[12957389,6957228],[13682769,6656768],[14379209,6294227],[15041405,5872366],[15664297,5394401],[16243171,4863960],[16758641,4301424],[17251579,3662185],[17673439,3000000],[18035980,2303556],[18336441,1578177],[18572539,829368],[18750748,0],[19758422,0],[19727293,236479],[19538467,1088188],[19276136,1920196],[18942292,2726179],[18539460,3499999],[18070731,4235755],[17539650,4927877],[16950279,5571067],[16307090,6160437],[15614974,6691519],[14879209,7160248],[14105392,7563079],[13299407,7896927],[12467399,8159255],[11615691,8348082],[10750769,8461952],[9879211,8500000],[9007652,8461952],[8142729,8348082],[7291022,8159255],[6459015,7896927],[5653029,7563079],[4879210,7160247],[4143447,6691519],[3451331,6160437],[2808141,5571066],[2218773,4927878],[1687689,4235755],[1218962,3499999],[827499,2748020],[482284,1920196],[219954,1088186],[31126,236479],[0,0],[1005754,0]),
+    );
+    my $res = $expolygon->medial_axis(scale 1.324888, scale 0.25);
+    is scalar(@$res), 1, 'medial axis of a semicircumference is a single line';
     
+    # check whether turns are all CCW or all CW
+    my @lines = @{$res->[0]->lines};
+    my @angles = map { $lines[$_-1]->ccw($lines[$_]->b) } 1..$#lines;
+    ok !!(none { $_ < 0 } @angles) || (none { $_ > 0 } @angles),
+        'all medial axis segments of a semicircumference have the same orientation';
 }
 
 {
@@ -136,7 +149,7 @@ if (0) {
 {
     my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new_scale(
         [50, 100],
-        [300, 102],
+        [1000, 102],
         [50, 104],
     ));
     my $res = $expolygon->medial_axis(scale 4, scale 0.5);
diff --git a/xs/src/libslic3r/ExPolygon.cpp b/xs/src/libslic3r/ExPolygon.cpp
index c84812fdfd..3640d39188 100644
--- a/xs/src/libslic3r/ExPolygon.cpp
+++ b/xs/src/libslic3r/ExPolygon.cpp
@@ -174,17 +174,10 @@ void
 ExPolygon::medial_axis(double max_width, double min_width, ThickPolylines* polylines) const
 {
     // init helper object
-    Slic3r::Geometry::MedialAxis ma(max_width, min_width);
-    ma.expolygon = this;
+    Slic3r::Geometry::MedialAxis ma(max_width, min_width, this);
+    ma.lines = this->lines();
     
-    // populate list of segments for the Voronoi diagram
-    ma.lines = this->contour.lines();
-    for (Polygons::const_iterator hole = this->holes.begin(); hole != this->holes.end(); ++hole) {
-        Lines lines = hole->lines();
-        ma.lines.insert(ma.lines.end(), lines.begin(), lines.end());
-    }
-    
-    // compute the Voronoi diagram
+    // compute the Voronoi diagram and extract medial axis polylines
     ThickPolylines pp;
     ma.build(&pp);
     
@@ -195,15 +188,14 @@ ExPolygon::medial_axis(double max_width, double min_width, ThickPolylines* polyl
     svg.Close();
     */
     
-    // find the maximum width returned
+    /* Find the maximum width returned; we're going to use this for validating and 
+       filtering the output segments. */
     double max_w = 0;
-    if (!pp.empty()) {
-        std::vector<double> widths;
-        for (ThickPolylines::const_iterator it = pp.begin(); it != pp.end(); ++it)
-            widths.insert(widths.end(), it->width.begin(), it->width.end());
-        max_w = *std::max_element(widths.begin(), widths.end());
-    }
+    for (ThickPolylines::const_iterator it = pp.begin(); it != pp.end(); ++it)
+        max_w = fmaxf(max_w, *std::max_element(it->width.begin(), it->width.end()));
     
+    /* Loop through all returned polylines in order to extend their endpoints to the 
+       expolygon boundaries */
     bool removed = false;
     for (size_t i = 0; i < pp.size(); ++i) {
         ThickPolyline& polyline = pp[i];
@@ -502,4 +494,15 @@ ExPolygon::lines() const
     return lines;
 }
 
+std::string
+ExPolygon::dump_perl() const
+{
+    std::ostringstream ret;
+    ret << "[" << this->contour.dump_perl();
+    for (Polygons::const_iterator h = this->holes.begin(); h != this->holes.end(); ++h)
+        ret << "," << h->dump_perl();
+    ret << "]";
+    return ret.str();
+}
+
 }
diff --git a/xs/src/libslic3r/ExPolygon.hpp b/xs/src/libslic3r/ExPolygon.hpp
index f23178cc08..69fe9fb0ee 100644
--- a/xs/src/libslic3r/ExPolygon.hpp
+++ b/xs/src/libslic3r/ExPolygon.hpp
@@ -42,6 +42,7 @@ class ExPolygon
     void triangulate_pp(Polygons* polygons) const;
     void triangulate_p2t(Polygons* polygons) const;
     Lines lines() const;
+    std::string dump_perl() const;
 };
 
 }
diff --git a/xs/src/libslic3r/Geometry.cpp b/xs/src/libslic3r/Geometry.cpp
index d4528e8645..6d864f6313 100644
--- a/xs/src/libslic3r/Geometry.cpp
+++ b/xs/src/libslic3r/Geometry.cpp
@@ -324,7 +324,7 @@ MedialAxis::build(ThickPolylines* polylines)
             if (edge->is_secondary() || edge->is_infinite()) continue;
         
             // don't re-validate twins
-            if (seen_edges.find(&*edge) != seen_edges.end()) continue;
+            if (seen_edges.find(&*edge) != seen_edges.end()) continue;  // TODO: is this needed?
             seen_edges.insert(&*edge);
             seen_edges.insert(edge->twin());
             
@@ -445,49 +445,66 @@ MedialAxis::validate_edge(const VD::edge_type* edge)
     }
     
     // retrieve the original line segments which generated the edge we're checking
-    const VD::cell_type* cell1 = edge->cell();
-    const VD::cell_type* cell2 = edge->twin()->cell();
-    const Line &segment1 = this->retrieve_segment(cell1);
-    const Line &segment2 = this->retrieve_segment(cell2);
+    const VD::cell_type* cell_l = edge->cell();
+    const VD::cell_type* cell_r = edge->twin()->cell();
+    const Line &segment_l = this->retrieve_segment(cell_l);
+    const Line &segment_r = this->retrieve_segment(cell_r);
     
-    /*  Calculate thickness of the section at both the endpoints of this edge.
-        Our Voronoi edge is part of a CCW sequence going around its Voronoi cell
-        (segment1). This edge's twin goes around segment2. Thus, segment2 is 
-        oriented in the same direction as our main edge, and segment1 is oriented
+    /*
+    SVG svg("edge.svg");
+    svg.draw(*this->expolygon);
+    svg.draw(line);
+    svg.draw(segment_l, "red");
+    svg.draw(segment_r, "blue");
+    svg.Close();
+    */
+    
+    /*  Calculate thickness of the cross-section at both the endpoints of this edge.
+        Our Voronoi edge is part of a CCW sequence going around its Voronoi cell 
+        located on the left side. (segment_l).
+        This edge's twin goes around segment_r. Thus, segment_r is 
+        oriented in the same direction as our main edge, and segment_l is oriented
         in the same direction as our twin edge.
-        We used to only consider the (half-)distances to segment2, and that works
-        whenever segment1 and segment2 are almost specular and facing. However, 
+        We used to only consider the (half-)distances to segment_r, and that works
+        whenever segment_l and segment_r are almost specular and facing. However, 
         at curves they are staggered and they only face for a very little length
-        (such visibility actually coincides with our very short edge). This is why
-        we calculate w0 and w1 this way.
-        When cell1 or cell2 don't refer to the segment but only to an endpoint, we
+        (our very short edge represents such visibility).
+        Both w0 and w1 can be calculated either towards cell_l or cell_r with equal
+        results by Voronoi definition.
+        When cell_l or cell_r don't refer to the segment but only to an endpoint, we
         calculate the distance to that endpoint instead.  */
     
-    coordf_t w0 = cell2->contains_segment()
-        ? line.a.perp_distance_to(segment2)*2
-        : line.a.distance_to(this->retrieve_endpoint(cell2))*2;
+    coordf_t w0 = cell_r->contains_segment()
+        ? line.a.distance_to(segment_r)*2
+        : line.a.distance_to(this->retrieve_endpoint(cell_r))*2;
     
-    coordf_t w1 = cell1->contains_segment()
-        ? line.b.perp_distance_to(segment1)*2
-        : line.b.distance_to(this->retrieve_endpoint(cell1))*2;
+    coordf_t w1 = cell_l->contains_segment()
+        ? line.b.distance_to(segment_l)*2
+        : line.b.distance_to(this->retrieve_endpoint(cell_l))*2;
     
-    // if this edge is the centerline for a very thin area, we might want to skip it
-    // in case the area is too thin
-    if (w0 < SCALED_EPSILON || w1 < SCALED_EPSILON) {
-        if (cell1->contains_segment() && cell2->contains_segment()) {
-            // calculate the relative angle between the two boundary segments
-            double angle = fabs(segment2.orientation() - segment1.orientation());
+    if (cell_l->contains_segment() && cell_r->contains_segment()) {
+        // calculate the relative angle between the two boundary segments
+        double angle = fabs(segment_r.orientation() - segment_l.orientation());
+        if (angle > PI) angle = 2*PI - angle;
+        assert(angle >= 0 && angle <= PI);
+        
+        // fabs(angle) ranges from 0 (collinear, same direction) to PI (collinear, opposite direction)
+        // we're interested only in segments close to the second case (facing segments)
+        // so we allow some tolerance.
+        // this filter ensures that we're dealing with a narrow/oriented area (longer than thick)
+        // we don't run it on edges not generated by two segments (thus generated by one segment
+        // and the endpoint of another segment), since their orientation would not be meaningful
+        if (PI - angle > PI/8) {
+            // angle is not narrow enough
             
-            // fabs(angle) ranges from 0 (collinear, same direction) to PI (collinear, opposite direction)
-            // we're interested only in segments close to the second case (facing segments)
-            // so we allow some tolerance.
-            // this filter ensures that we're dealing with a narrow/oriented area (longer than thick)
-            // we don't run it on edges not generated by two segments (thus generated by one segment
-            // and the endpoint of another segment), since their orientation would not be meaningful
-            if (fabs(angle - PI) > PI/5) return false;
-        } else {
-            return false;
+            // only apply this filter to segments that are not too short otherwise their 
+            // angle could possibly be not meaningful
+            if (w0 < SCALED_EPSILON || w1 < SCALED_EPSILON || line.length() >= this->min_width)
+                return false;
         }
+    } else {
+        if (w0 < SCALED_EPSILON || w1 < SCALED_EPSILON)
+            return false;
     }
     
     if (w0 < this->min_width && w1 < this->min_width)
diff --git a/xs/src/libslic3r/Geometry.hpp b/xs/src/libslic3r/Geometry.hpp
index af4667d42c..14bc3f0ca8 100644
--- a/xs/src/libslic3r/Geometry.hpp
+++ b/xs/src/libslic3r/Geometry.hpp
@@ -46,8 +46,8 @@ class MedialAxis {
     const ExPolygon* expolygon;
     double max_width;
     double min_width;
-    MedialAxis(double _max_width, double _min_width)
-        : max_width(_max_width), min_width(_min_width), expolygon(NULL) {};
+    MedialAxis(double _max_width, double _min_width, const ExPolygon* _expolygon = NULL)
+        : max_width(_max_width), min_width(_min_width), expolygon(_expolygon) {};
     void build(ThickPolylines* polylines);
     void build(Polylines* polylines);
     
diff --git a/xs/src/libslic3r/Line.cpp b/xs/src/libslic3r/Line.cpp
index c98750e846..c7afc80c74 100644
--- a/xs/src/libslic3r/Line.cpp
+++ b/xs/src/libslic3r/Line.cpp
@@ -212,6 +212,12 @@ Line::intersection(const Line& line, Point* intersection) const
     return false;  // not intersecting
 }
 
+double
+Line::ccw(const Point& point) const
+{
+    return point.ccw(*this);
+}
+
 Pointf3
 Linef3::intersect_plane(double z) const
 {
diff --git a/xs/src/libslic3r/Line.hpp b/xs/src/libslic3r/Line.hpp
index ae1f4cb7d0..42e811449c 100644
--- a/xs/src/libslic3r/Line.hpp
+++ b/xs/src/libslic3r/Line.hpp
@@ -44,6 +44,7 @@ class Line
     void extend_end(double distance);
     void extend_start(double distance);
     bool intersection(const Line& line, Point* intersection) const;
+    double ccw(const Point& point) const;
 };
 
 class ThickLine : public Line
diff --git a/xs/src/libslic3r/MultiPoint.cpp b/xs/src/libslic3r/MultiPoint.cpp
index ff2771cff5..6857d6393e 100644
--- a/xs/src/libslic3r/MultiPoint.cpp
+++ b/xs/src/libslic3r/MultiPoint.cpp
@@ -128,6 +128,19 @@ MultiPoint::intersection(const Line& line, Point* intersection) const
     return false;
 }
 
+std::string
+MultiPoint::dump_perl() const
+{
+    std::ostringstream ret;
+    ret << "[";
+    for (Points::const_iterator p = this->points.begin(); p != this->points.end(); ++p) {
+        ret << p->dump_perl();
+        if (p != this->points.end()-1) ret << ",";
+    }
+    ret << "]";
+    return ret.str();
+}
+
 Points
 MultiPoint::_douglas_peucker(const Points &points, const double tolerance)
 {
diff --git a/xs/src/libslic3r/MultiPoint.hpp b/xs/src/libslic3r/MultiPoint.hpp
index 18d67a9e4c..d057b14f12 100644
--- a/xs/src/libslic3r/MultiPoint.hpp
+++ b/xs/src/libslic3r/MultiPoint.hpp
@@ -37,6 +37,7 @@ class MultiPoint
     void append(const Points &points);
     void append(const Points::const_iterator &begin, const Points::const_iterator &end);
     bool intersection(const Line& line, Point* intersection) const;
+    std::string dump_perl() const;
     
     static Points _douglas_peucker(const Points &points, const double tolerance);
 };
diff --git a/xs/src/libslic3r/PerimeterGenerator.cpp b/xs/src/libslic3r/PerimeterGenerator.cpp
index d7fdcbfae2..7bb207e000 100644
--- a/xs/src/libslic3r/PerimeterGenerator.cpp
+++ b/xs/src/libslic3r/PerimeterGenerator.cpp
@@ -92,7 +92,7 @@ PerimeterGenerator::process()
                         
                         // the following offset2 ensures almost nothing in @thin_walls is narrower than $min_width
                         // (actually, something larger than that still may exist due to mitering or other causes)
-                        coord_t min_width = scale_(this->ext_perimeter_flow.nozzle_diameter / 2);
+                        coord_t min_width = scale_(this->ext_perimeter_flow.nozzle_diameter / 3);
                         ExPolygons expp = offset2_ex(diffpp, -min_width/2, +min_width/2);
                         
                         // the maximum thickness of our thin wall area is equal to the minimum thickness of a single loop
diff --git a/xs/src/libslic3r/Point.cpp b/xs/src/libslic3r/Point.cpp
index dc9d510c69..29ce0b1532 100644
--- a/xs/src/libslic3r/Point.cpp
+++ b/xs/src/libslic3r/Point.cpp
@@ -26,6 +26,14 @@ Point::wkt() const
     return ss.str();
 }
 
+std::string
+Point::dump_perl() const
+{
+    std::ostringstream ss;
+    ss << "[" << this->x << "," << this->y << "]";
+    return ss.str();
+}
+
 void
 Point::scale(double factor)
 {
@@ -313,6 +321,14 @@ Pointf::wkt() const
     return ss.str();
 }
 
+std::string
+Pointf::dump_perl() const
+{
+    std::ostringstream ss;
+    ss << "[" << this->x << "," << this->y << "]";
+    return ss.str();
+}
+
 void
 Pointf::scale(double factor)
 {
diff --git a/xs/src/libslic3r/Point.hpp b/xs/src/libslic3r/Point.hpp
index dbd1219b9e..6638e0eb3f 100644
--- a/xs/src/libslic3r/Point.hpp
+++ b/xs/src/libslic3r/Point.hpp
@@ -38,6 +38,7 @@ class Point
     };
     bool operator==(const Point& rhs) const;
     std::string wkt() const;
+    std::string dump_perl() const;
     void scale(double factor);
     void translate(double x, double y);
     void translate(const Vector &vector);
@@ -87,6 +88,7 @@ class Pointf
         return Pointf(unscale(p.x), unscale(p.y));
     };
     std::string wkt() const;
+    std::string dump_perl() const;
     void scale(double factor);
     void translate(double x, double y);
     void translate(const Vectorf &vector);
diff --git a/xs/xsp/Line.xsp b/xs/xsp/Line.xsp
index 461856a1a6..92429e57a8 100644
--- a/xs/xsp/Line.xsp
+++ b/xs/xsp/Line.xsp
@@ -41,6 +41,8 @@
         %code{% RETVAL = Polyline(*THIS); %};
     Clone<Point> normal();
     Clone<Point> vector();
+    double ccw(Point* point)
+        %code{% RETVAL = THIS->ccw(*point); %};
 %{
 
 Line*

From ea9b10c7640e5a293024dc19f0f2babbdb347701 Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lenox.joseph@gmail.com>
Date: Sun, 29 May 2016 10:56:21 -0500
Subject: [PATCH 06/13] Added a short OpenSCAD description to aid in the
 creation of simple modifier meshes that describe a change every N layers

---
 utils/modifier_helpers/solid_layers.scad | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 utils/modifier_helpers/solid_layers.scad

diff --git a/utils/modifier_helpers/solid_layers.scad b/utils/modifier_helpers/solid_layers.scad
new file mode 100644
index 0000000000..80a92fee03
--- /dev/null
+++ b/utils/modifier_helpers/solid_layers.scad
@@ -0,0 +1,24 @@
+// Used to generate a modifier mesh to do something every few layers. 
+// Load into OpenSCAD, tweak the variables below, export as STL and load as 
+// a modifier mesh. Then change settings for the modifier mesh.
+
+// Written by Joseph Lenox; in public domain.
+
+layer_height = 0.3; // set to layer height in slic3r for "best" results.
+number_of_solid_layers = 2;
+N = 4; // N > number_of_solid_layers or else the whole thing will be solid
+model_height = 300.0;
+model_width = 300.0; // these two should be at least as big as the model 
+model_depth = 300.0; // but bigger isn't a problem
+initial_offset=0; // don't generate below this
+
+position_on_bed=[0,0,0]; // in case you need to move it around
+
+// don't touch below unless you know what you are doing.
+simple_layers = round(model_height/0.3);
+translate(position_on_bed)
+  for (i = [initial_offset:N:simple_layers]) {
+    translate([0,0,i*layer_height])
+      translate([0,0,(layer_height*number_of_solid_layers)/2])
+      cube([model_width,model_depth,layer_height*number_of_solid_layers], center=true);
+  }

From 30f6e4b16f94b167b28521d71786aeea7cc4585b Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Tue, 24 May 2016 03:47:21 +0200
Subject: [PATCH 07/13] Bugfix: homing was not correctly saved

---
 lib/Slic3r/GUI/Controller/ManualControlDialog.pm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/Slic3r/GUI/Controller/ManualControlDialog.pm b/lib/Slic3r/GUI/Controller/ManualControlDialog.pm
index 399c397cb6..a8209f9888 100644
--- a/lib/Slic3r/GUI/Controller/ManualControlDialog.pm
+++ b/lib/Slic3r/GUI/Controller/ManualControlDialog.pm
@@ -182,8 +182,8 @@ sub home {
     
     $self->sender->send(sprintf("G28 %s", $axis), 1);
     $self->{canvas}->set_pos(undef);
-    $self->x_homed if $axis eq 'X';
-    $self->y_homed if $axis eq 'Y';
+    $self->x_homed(1) if $axis eq 'X';
+    $self->y_homed(1) if $axis eq 'Y';
 }
 
 1;

From 2a8c139ca42c759a590bb72a23257140789399a9 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Tue, 24 May 2016 03:54:52 +0200
Subject: [PATCH 08/13] Add XYZ homing button to printer manual control

---
 lib/Slic3r/GUI/Controller/ManualControlDialog.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/Slic3r/GUI/Controller/ManualControlDialog.pm b/lib/Slic3r/GUI/Controller/ManualControlDialog.pm
index a8209f9888..ebd0031a9c 100644
--- a/lib/Slic3r/GUI/Controller/ManualControlDialog.pm
+++ b/lib/Slic3r/GUI/Controller/ManualControlDialog.pm
@@ -87,7 +87,8 @@ sub new {
         $bed_sizer->Add($sizer, 1, wxEXPAND, 0);
     }
     
-    $bed_sizer->AddSpacer(0);
+    # XYZ home button
+    $move_button->($bed_sizer, 'XYZ', 'house', 1, wxTOP, sub { $self->home(undef) });
     
     # X buttons
     {
@@ -180,6 +181,7 @@ sub rel_move {
 sub home {
     my ($self, $axis) = @_;
     
+    $axis //= '';
     $self->sender->send(sprintf("G28 %s", $axis), 1);
     $self->{canvas}->set_pos(undef);
     $self->x_homed(1) if $axis eq 'X';

From 08a2775dbdc54179c755095f3d9c81c4303f5fee Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lordofhyphens@gmail.com>
Date: Tue, 31 May 2016 19:14:20 -0500
Subject: [PATCH 09/13] Update solid_layers.scad

Oops, left a hardcoded 0.3 in. Fixed.
---
 utils/modifier_helpers/solid_layers.scad | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/utils/modifier_helpers/solid_layers.scad b/utils/modifier_helpers/solid_layers.scad
index 80a92fee03..3782949495 100644
--- a/utils/modifier_helpers/solid_layers.scad
+++ b/utils/modifier_helpers/solid_layers.scad
@@ -15,7 +15,7 @@ initial_offset=0; // don't generate below this
 position_on_bed=[0,0,0]; // in case you need to move it around
 
 // don't touch below unless you know what you are doing.
-simple_layers = round(model_height/0.3);
+simple_layers = round(model_height/layer_height);
 translate(position_on_bed)
   for (i = [initial_offset:N:simple_layers]) {
     translate([0,0,i*layer_height])

From 39dfee79c71507ec67edb872e3eef88ded670282 Mon Sep 17 00:00:00 2001
From: Vanessa Ezekowitz <vanessaezekowitz@gmail.com>
Date: Wed, 1 Jun 2016 17:47:54 -0400
Subject: [PATCH 10/13] Mention anti-ooze sacrificial skirt feature.

---
 xs/src/libslic3r/PrintConfig.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xs/src/libslic3r/PrintConfig.cpp b/xs/src/libslic3r/PrintConfig.cpp
index 6fcb0864e2..47609aaff8 100644
--- a/xs/src/libslic3r/PrintConfig.cpp
+++ b/xs/src/libslic3r/PrintConfig.cpp
@@ -1015,7 +1015,7 @@ PrintConfigDef::PrintConfigDef()
 
     def = this->add("standby_temperature_delta", coInt);
     def->label = "Temperature variation";
-    def->tooltip = "Temperature difference to be applied when an extruder is not active.";
+    def->tooltip = "Temperature difference to be applied when an extruder is not active.  Enables a full-height \"sacrificial\" skirt on which the nozzles are periodically wiped.";
     def->sidetext = "∆°C";
     def->cli = "standby-temperature-delta=i";
     def->min = -500;

From 5e1774642796ae04dc048e92b13bfe7a96ed1598 Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lordofhyphens@gmail.com>
Date: Thu, 2 Jun 2016 11:43:34 -0500
Subject: [PATCH 11/13] Post process script for fan kickstart

Addresses #3308
---
 utils/post-processing/fan_kickstart.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 utils/post-processing/fan_kickstart.py

diff --git a/utils/post-processing/fan_kickstart.py b/utils/post-processing/fan_kickstart.py
new file mode 100644
index 0000000000..9ee1bc0a4a
--- /dev/null
+++ b/utils/post-processing/fan_kickstart.py
@@ -0,0 +1,13 @@
+#!/usr/bin/python
+import sys
+import re
+
+sea = re.compile("M106 S[1-9]+[0-9]*")
+rep = re.compile("M106 S255\n\g<0>")
+out = open(sys.argv[1]+"_fixed", 'w')
+  with open(sys.argv[1]) as f:
+    for r in f:
+      if re.search(sea, r) is not None:
+        out.write(re.sub(sea,"M106 S255\n\g<0>",r))
+      else:
+        out.write(r)

From 223065221888e202a762bfeaff125f960896b009 Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lordofhyphens@gmail.com>
Date: Thu, 2 Jun 2016 19:18:29 -0500
Subject: [PATCH 12/13] Added simple JSCAD modifier helper

Simple cube oriented around the center with a parametric interface. Just copy/paste into openjscad.org and hit shift+enter.
---
 utils/modifier_helpers/layer_generator.jscad | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 utils/modifier_helpers/layer_generator.jscad

diff --git a/utils/modifier_helpers/layer_generator.jscad b/utils/modifier_helpers/layer_generator.jscad
new file mode 100644
index 0000000000..fc193a53f9
--- /dev/null
+++ b/utils/modifier_helpers/layer_generator.jscad
@@ -0,0 +1,19 @@
+// title: Layer_generator
+// written by: Joseph Lenox
+// Used for generating cubes oriented about the center 
+// for making simple modifier meshes.
+
+var width = 100;
+var layer_height = 0.3;
+var z = 30;
+function main() {
+    
+    return cube(size=[width,width,layer_height], center=true).translate([0,0,z]);    
+}
+function getParameterDefinitions() {
+  return [
+      { name: 'width', type: 'float', initial: 100, caption: "Width of the cube:" },
+      { name: 'layer_height', type: 'float', initial: 0.3, caption: "Layer height used:" },
+      { name: 'z', type: 'float', initial: 0, caption: "Z:" }
+  ];
+}

From 36231347f9bd683c5196d3ee6e1e2447ac5ced95 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Mon, 20 Jun 2016 21:02:15 +0200
Subject: [PATCH 13/13] Partially ported Format::STL and Format::OBJ to XS

---
 xs/MANIFEST                       |  2 ++
 xs/src/admesh/shared.c            |  2 +-
 xs/src/admesh/stl.h               |  6 ++--
 xs/src/admesh/stlinit.c           |  4 +--
 xs/src/libslic3r/IO.cpp           | 47 +++++++++++++++++++++++++++++++
 xs/src/libslic3r/IO.hpp           | 26 +++++++++++++++++
 xs/src/libslic3r/TriangleMesh.cpp | 16 +++++------
 xs/src/libslic3r/TriangleMesh.hpp |  8 +++---
 xs/xsp/TriangleMesh.xsp           |  8 +++---
 9 files changed, 97 insertions(+), 22 deletions(-)
 create mode 100644 xs/src/libslic3r/IO.cpp
 create mode 100644 xs/src/libslic3r/IO.hpp

diff --git a/xs/MANIFEST b/xs/MANIFEST
index 0f541515da..4e544d472c 100644
--- a/xs/MANIFEST
+++ b/xs/MANIFEST
@@ -38,6 +38,8 @@ src/libslic3r/GCodeWriter.cpp
 src/libslic3r/GCodeWriter.hpp
 src/libslic3r/Geometry.cpp
 src/libslic3r/Geometry.hpp
+src/libslic3r/IO.cpp
+src/libslic3r/IO.hpp
 src/libslic3r/Layer.cpp
 src/libslic3r/Layer.hpp
 src/libslic3r/LayerRegion.cpp
diff --git a/xs/src/admesh/shared.c b/xs/src/admesh/shared.c
index 56164e25fc..19c7da70ec 100644
--- a/xs/src/admesh/shared.c
+++ b/xs/src/admesh/shared.c
@@ -234,7 +234,7 @@ stl_write_vrml(stl_file *stl, char *file) {
   fclose(fp);
 }
 
-void stl_write_obj (stl_file *stl, char *file) {
+void stl_write_obj (stl_file *stl, const char *file) {
   int i;
   FILE* fp;
 
diff --git a/xs/src/admesh/stl.h b/xs/src/admesh/stl.h
index 25fe770aa8..3013a887c9 100644
--- a/xs/src/admesh/stl.h
+++ b/xs/src/admesh/stl.h
@@ -135,7 +135,7 @@ typedef struct {
 } stl_file;
 
 
-extern void stl_open(stl_file *stl, char *file);
+extern void stl_open(stl_file *stl, const char *file);
 extern void stl_close(stl_file *stl);
 extern void stl_stats_out(stl_file *stl, FILE *file, char *input_file);
 extern void stl_print_edges(stl_file *stl, FILE *file);
@@ -171,7 +171,7 @@ extern void stl_mirror_xz(stl_file *stl);
 extern void stl_open_merge(stl_file *stl, char *file);
 extern void stl_invalidate_shared_vertices(stl_file *stl);
 extern void stl_generate_shared_vertices(stl_file *stl);
-extern void stl_write_obj(stl_file *stl, char *file);
+extern void stl_write_obj(stl_file *stl, const char *file);
 extern void stl_write_off(stl_file *stl, char *file);
 extern void stl_write_dxf(stl_file *stl, char *file, char *label);
 extern void stl_write_vrml(stl_file *stl, char *file);
@@ -182,7 +182,7 @@ extern void stl_calculate_volume(stl_file *stl);
 extern void stl_repair(stl_file *stl, int fixall_flag, int exact_flag, int tolerance_flag, float tolerance, int increment_flag, float increment, int nearby_flag, int iterations, int remove_unconnected_flag, int fill_holes_flag, int normal_directions_flag, int normal_values_flag, int reverse_all_flag, int verbose_flag);
 
 extern void stl_initialize(stl_file *stl);
-extern void stl_count_facets(stl_file *stl, char *file);
+extern void stl_count_facets(stl_file *stl, const char *file);
 extern void stl_allocate(stl_file *stl);
 extern void stl_read(stl_file *stl, int first_facet, int first);
 extern void stl_facet_stats(stl_file *stl, stl_facet facet, int first);
diff --git a/xs/src/admesh/stlinit.c b/xs/src/admesh/stlinit.c
index 3a5de90525..58f6947c73 100644
--- a/xs/src/admesh/stlinit.c
+++ b/xs/src/admesh/stlinit.c
@@ -34,7 +34,7 @@
 #endif
 
 void
-stl_open(stl_file *stl, char *file) {
+stl_open(stl_file *stl, const char *file) {
   stl_initialize(stl);
   stl_count_facets(stl, file);
   stl_allocate(stl);
@@ -65,7 +65,7 @@ stl_initialize(stl_file *stl) {
 }
 
 void
-stl_count_facets(stl_file *stl, char *file) {
+stl_count_facets(stl_file *stl, const char *file) {
   long           file_size;
   int            header_num_facets;
   int            num_facets;
diff --git a/xs/src/libslic3r/IO.cpp b/xs/src/libslic3r/IO.cpp
new file mode 100644
index 0000000000..81ac8a127e
--- /dev/null
+++ b/xs/src/libslic3r/IO.cpp
@@ -0,0 +1,47 @@
+#include "IO.hpp"
+#include <stdexcept>
+
+namespace Slic3r { namespace IO {
+
+bool
+STL::read_file(std::string input_file, Model* model)
+{
+    // TODO: encode file name
+    // TODO: check that file exists
+    
+    TriangleMesh mesh;
+    mesh.ReadSTLFile(input_file);
+    mesh.repair();
+    
+    if (mesh.facets_count() == 0)
+        throw std::runtime_error("This STL file couldn't be read because it's empty.");
+    
+    ModelObject* object = model->add_object();
+    object->name        = input_file;  // TODO: use basename()
+    object->input_file  = input_file;
+    
+    ModelVolume* volume = object->add_volume(mesh);
+    volume->name        = input_file;   // TODO: use basename()
+    
+    return true;
+}
+
+bool
+STL::write(TriangleMesh& mesh, std::string output_file, bool binary)
+{
+    if (binary) {
+        mesh.write_binary(output_file);
+    } else {
+        mesh.write_ascii(output_file);
+    }
+    return true;
+}
+
+bool
+OBJ::write(TriangleMesh& mesh, std::string output_file)
+{
+    mesh.WriteOBJFile(output_file);
+    return true;
+}
+
+} }
diff --git a/xs/src/libslic3r/IO.hpp b/xs/src/libslic3r/IO.hpp
new file mode 100644
index 0000000000..248f3be540
--- /dev/null
+++ b/xs/src/libslic3r/IO.hpp
@@ -0,0 +1,26 @@
+#ifndef slic3r_IO_hpp_
+#define slic3r_IO_hpp_
+
+#include "libslic3r.h"
+#include "Model.hpp"
+#include "TriangleMesh.hpp"
+#include <string>
+
+namespace Slic3r { namespace IO {
+
+class STL
+{
+    public:
+    bool read_file(std::string input_file, Model* model);
+    bool write(TriangleMesh& mesh, std::string output_file, bool binary = true);
+};
+
+class OBJ
+{
+    public:
+    bool write(TriangleMesh& mesh, std::string output_file);
+};
+
+} }
+
+#endif
diff --git a/xs/src/libslic3r/TriangleMesh.cpp b/xs/src/libslic3r/TriangleMesh.cpp
index 484fee9fc1..40d0e480b1 100644
--- a/xs/src/libslic3r/TriangleMesh.cpp
+++ b/xs/src/libslic3r/TriangleMesh.cpp
@@ -70,20 +70,20 @@ TriangleMesh::~TriangleMesh() {
 }
 
 void
-TriangleMesh::ReadSTLFile(char* input_file) {
-    stl_open(&stl, input_file);
+TriangleMesh::ReadSTLFile(const std::string &input_file) {
+    stl_open(&stl, input_file.c_str());
 }
 
 void
-TriangleMesh::write_ascii(char* output_file)
+TriangleMesh::write_ascii(const std::string &output_file)
 {
-    stl_write_ascii(&this->stl, output_file, "");
+    stl_write_ascii(&this->stl, output_file.c_str(), "");
 }
 
 void
-TriangleMesh::write_binary(char* output_file)
+TriangleMesh::write_binary(const std::string &output_file)
 {
-    stl_write_binary(&this->stl, output_file, "");
+    stl_write_binary(&this->stl, output_file.c_str(), "");
 }
 
 void
@@ -173,9 +173,9 @@ TriangleMesh::facets_count() const
 }
 
 void
-TriangleMesh::WriteOBJFile(char* output_file) {
+TriangleMesh::WriteOBJFile(const std::string &output_file) {
     stl_generate_shared_vertices(&stl);
-    stl_write_obj(&stl, output_file);
+    stl_write_obj(&stl, output_file.c_str());
 }
 
 void TriangleMesh::scale(float factor)
diff --git a/xs/src/libslic3r/TriangleMesh.hpp b/xs/src/libslic3r/TriangleMesh.hpp
index cf129809a2..0eb62d65e0 100644
--- a/xs/src/libslic3r/TriangleMesh.hpp
+++ b/xs/src/libslic3r/TriangleMesh.hpp
@@ -24,11 +24,11 @@ class TriangleMesh
     TriangleMesh& operator= (TriangleMesh other);
     void swap(TriangleMesh &other);
     ~TriangleMesh();
-    void ReadSTLFile(char* input_file);
-    void write_ascii(char* output_file);
-    void write_binary(char* output_file);
+    void ReadSTLFile(const std::string &input_file);
+    void write_ascii(const std::string &output_file);
+    void write_binary(const std::string &output_file);
     void repair();
-    void WriteOBJFile(char* output_file);
+    void WriteOBJFile(const std::string &output_file);
     void scale(float factor);
     void scale(const Pointf3 &versor);
     void translate(float x, float y, float z);
diff --git a/xs/xsp/TriangleMesh.xsp b/xs/xsp/TriangleMesh.xsp
index c7324f98d1..7c13cb7f4a 100644
--- a/xs/xsp/TriangleMesh.xsp
+++ b/xs/xsp/TriangleMesh.xsp
@@ -10,11 +10,11 @@
     ~TriangleMesh();
     Clone<TriangleMesh> clone()
         %code{% RETVAL = THIS; %};
-    void ReadSTLFile(char* input_file);
-    void write_ascii(char* output_file);
-    void write_binary(char* output_file);
+    void ReadSTLFile(std::string input_file);
+    void write_ascii(std::string output_file);
+    void write_binary(std::string output_file);
     void repair();
-    void WriteOBJFile(char* output_file);
+    void WriteOBJFile(std::string output_file);
     void scale(float factor);
     void scale_xyz(Pointf3* versor)
         %code{% THIS->scale(*versor); %};