Unicode handling:

Removed the Perl dependencies on Encode, Encode::Locale and Unicode::Normalize.
Added dependency on boost::locale.
Added encode_path, decode_path, normalize_utf8 functions to Slic3r.xs

Slic3r.xs has been made mostly utf8 safe by using the boost::nowide library,
thanks to @alexrj for the idea.

Simplified the encode_path / decode_path stuff:
wxWidgets are unicode already, so there is no need to decode_path() from it.
Perl / win32 interfacing is non-unicode, so decode_path() is executed
on ARGV just at the beginning of the perl scripts.

33 files changed, 236 insertions, 186 deletions

diff --git a/Build.PL b/Build.PL
index 196544846..0f340a585 100644
--- a/Build.PL
+++ b/Build.PL
@@ -8,8 +8,6 @@ use File::Spec;
 
 my %prereqs = qw(
     Devel::CheckLib                 0
-    Encode                          0
-    Encode::Locale                  1.05
     ExtUtils::MakeMaker             6.80
     ExtUtils::ParseXS               3.22
     File::Basename                  0
@@ -24,7 +22,6 @@ my %prereqs = qw(
     IO::Scalar                      0
     threads                         1.96
     Time::HiRes                     0
-    Unicode::Normalize              0
 );
 my %recommends = qw(
     Class::XSAccessor               0
diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index bdd326140..17b783269 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -75,20 +75,10 @@ use Slic3r::Print::Simple;
 use Slic3r::Surface;
 our $build = eval "use Slic3r::Build; 1";
 use Thread::Semaphore;
-use Encode::Locale 1.05;
-use Encode;
-use Unicode::Normalize;
 
 # Scaling between the float and integer coordinates.
 # Floats are in mm.
 use constant SCALING_FACTOR         => 0.000001;
-use constant LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER => 0.15;
-
-# Following constants are used by the infill algorithms and integration tests.
-# Resolution to simplify perimeters to. These constants are now used in C++ code only. Better to publish them to Perl from the C++ code.
-# use constant RESOLUTION             => 0.0125;
-# use constant SCALED_RESOLUTION      => RESOLUTION / SCALING_FACTOR;
-use constant INFILL_OVERLAP_OVER_SPACING  => 0.3;
 
 # Keep track of threads we created. Perl worker threads shall not create further threads.
 my @threads = ();
@@ -211,39 +201,6 @@ sub resume_all_threads {
     $pause_sema->up;
 }
 
-# Convert a Unicode path to a file system locale.
-# The encoding is (from Encode::Locale POD):
-# Alias       | Windows | Mac OS X     | POSIX
-# locale_fs   | ANSI    | UTF-8        | nl_langinfo
-# where nl_langinfo is en-US.UTF-8 on a modern Linux as well.
-# So this conversion seems to make the most sense on Windows.
-sub encode_path {
-    my ($path) = @_;
-
-    # UTF8 encoding is not unique. Normalize the UTF8 string to make the file names unique.
-    # Unicode::Normalize::NFC() returns the Normalization Form C (formed by canonical decomposition followed by canonical composition).
-    $path = Unicode::Normalize::NFC($path);
-    $path = Encode::encode(locale_fs => $path);
-    
-    return $path;
-}
-
-# Convert a path coded by a file system locale to Unicode.
-sub decode_path {
-    my ($path) = @_;
-    
-    $path = Encode::decode(locale_fs => $path)
-        unless Encode::is_utf8($path);
-
-    # The filesystem might force a normalization form (like HFS+ does) so 
-    # if we rely on the filename being comparable after the open() + readdir()
-    # roundtrip (like when creating and then selecting a preset), we need to 
-    # restore our normalization form.
-    $path = Unicode::Normalize::NFC($path);
-    
-    return $path;
-}
-
 # Open a file by converting $filename to local file system locales.
 sub open {
     my ($fh, $mode, $filename) = @_;
diff --git a/lib/Slic3r/GUI.pm b/lib/Slic3r/GUI.pm
index ccf0e9c9b..cf2729c92 100644
--- a/lib/Slic3r/GUI.pm
+++ b/lib/Slic3r/GUI.pm
@@ -101,7 +101,7 @@ sub OnInit {
     # Unix: ~/.Slic3r
     # Windows: "C:\Users\username\AppData\Roaming\Slic3r" or "C:\Documents and Settings\username\Application Data\Slic3r"
     # Mac: "~/Library/Application Support/Slic3r"
-    $datadir ||= Slic3r::decode_path(Wx::StandardPaths::Get->GetUserDataDir);
+    $datadir ||= Wx::StandardPaths::Get->GetUserDataDir;
     my $enc_datadir = Slic3r::encode_path($datadir);
     Slic3r::debugf "Data directory: %s\n", $datadir;
     
@@ -370,9 +370,8 @@ sub open_model {
         $dialog->Destroy;
         return;
     }
-    my @input_files = map Slic3r::decode_path($_), $dialog->GetPaths;
+    my @input_files = $dialog->GetPaths;
     $dialog->Destroy;
-    
     return @input_files;
 }
 
diff --git a/lib/Slic3r/GUI/BedShapeDialog.pm b/lib/Slic3r/GUI/BedShapeDialog.pm
index d71ceddba..70c8e0256 100644
--- a/lib/Slic3r/GUI/BedShapeDialog.pm
+++ b/lib/Slic3r/GUI/BedShapeDialog.pm
@@ -286,7 +286,7 @@ sub _load_stl {
         $dialog->Destroy;
         return;
     }
-    my $input_file = Slic3r::decode_path($dialog->GetPaths);
+    my $input_file = $dialog->GetPaths;
     $dialog->Destroy;
     
     my $model = Slic3r::Model->read_from_file($input_file);
diff --git a/lib/Slic3r/GUI/MainFrame.pm b/lib/Slic3r/GUI/MainFrame.pm
index f075b4b28..e15868fb6 100644
--- a/lib/Slic3r/GUI/MainFrame.pm
+++ b/lib/Slic3r/GUI/MainFrame.pm
@@ -368,7 +368,7 @@ sub quick_slice {
                 $dialog->Destroy;
                 return;
             }
-            $input_file = Slic3r::decode_path($dialog->GetPaths);
+            $input_file = $dialog->GetPaths;
             $dialog->Destroy;
             $qs_last_input_file = $input_file unless $params{export_svg};
         } else {
@@ -428,7 +428,7 @@ sub quick_slice {
                 $dlg->Destroy;
                 return;
             }
-            $output_file = Slic3r::decode_path($dlg->GetPath);
+            $output_file = $dlg->GetPath;
             $qs_last_output_file = $output_file unless $params{export_svg};
             $Slic3r::GUI::Settings->{_}{last_output_path} = dirname($output_file);
             wxTheApp->save_settings;
@@ -482,7 +482,7 @@ sub repair_stl {
             $dialog->Destroy;
             return;
         }
-        $input_file = Slic3r::decode_path($dialog->GetPaths);
+        $input_file = $dialog->GetPaths;
         $dialog->Destroy;
     }
     
@@ -495,14 +495,14 @@ sub repair_stl {
             $dlg->Destroy;
             return undef;
         }
-        $output_file = Slic3r::decode_path($dlg->GetPath);
+        $output_file = $dlg->GetPath;
         $dlg->Destroy;
     }
     
     my $tmesh = Slic3r::TriangleMesh->new;
-    $tmesh->ReadSTLFile(Slic3r::encode_path($input_file));
+    $tmesh->ReadSTLFile($input_file);
     $tmesh->repair;
-    $tmesh->WriteOBJFile(Slic3r::encode_path($output_file));
+    $tmesh->WriteOBJFile($output_file);
     Slic3r::GUI::show_info($self, "Your file was repaired.", "Repair");
 }
 
@@ -529,7 +529,7 @@ sub export_config {
     my $dlg = Wx::FileDialog->new($self, 'Save configuration as:', $dir, $filename, 
         &Slic3r::GUI::FILE_WILDCARDS->{ini}, wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
     if ($dlg->ShowModal == wxID_OK) {
-        my $file = Slic3r::decode_path($dlg->GetPath);
+        my $file = $dlg->GetPath;
         $Slic3r::GUI::Settings->{recent}{config_directory} = dirname($file);
         wxTheApp->save_settings;
         $last_config = $file;
@@ -548,7 +548,7 @@ sub load_config_file {
         my $dlg = Wx::FileDialog->new($self, 'Select configuration to load:', $dir, "config.ini", 
                 'INI files (*.ini, *.gcode)|*.ini;*.INI;*.gcode;*.g', wxFD_OPEN | wxFD_FILE_MUST_EXIST);
         return unless $dlg->ShowModal == wxID_OK;
-        $file = Slic3r::decode_path($dlg->GetPaths);
+        $file = $dlg->GetPaths;
         $dlg->Destroy;
     }
     for my $tab (values %{$self->{options_tabs}}) {
@@ -574,7 +574,7 @@ sub export_configbundle {
     my $dlg = Wx::FileDialog->new($self, 'Save presets bundle as:', $dir, $filename, 
         &Slic3r::GUI::FILE_WILDCARDS->{ini}, wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
     if ($dlg->ShowModal == wxID_OK) {
-        my $file = Slic3r::decode_path($dlg->GetPath);
+        my $file = $dlg->GetPath;
         $Slic3r::GUI::Settings->{recent}{config_directory} = dirname($file);
         wxTheApp->save_settings;
         
@@ -604,7 +604,7 @@ sub load_configbundle {
         my $dlg = Wx::FileDialog->new($self, 'Select configuration to load:', $dir, "config.ini", 
                 &Slic3r::GUI::FILE_WILDCARDS->{ini}, wxFD_OPEN | wxFD_FILE_MUST_EXIST);
         return unless $dlg->ShowModal == wxID_OK;
-        $file = Slic3r::decode_path($dlg->GetPaths);
+        $file = $dlg->GetPaths;
         $dlg->Destroy;
     }
     
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index c473688c2..91dca96b9 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -1408,7 +1408,7 @@ sub export_gcode {
             $dlg->Destroy;
             return;
         }
-        my $path = Slic3r::decode_path($dlg->GetPath);
+        my $path = $dlg->GetPath;
         $Slic3r::GUI::Settings->{_}{last_output_path} = dirname($path);
         wxTheApp->save_settings;
         $self->{export_gcode_output_file} = $path;
@@ -1574,7 +1574,7 @@ sub send_gcode {
     my $ua = LWP::UserAgent->new;
     $ua->timeout(180);
     
-    my $path = Slic3r::encode_path($self->{send_gcode_file});
+    my $enc_path = Slic3r::encode_path($self->{send_gcode_file});
     my $res = $ua->post(
         "http://" . $self->{config}->octoprint_host . "/api/files/local",
         Content_Type => 'form-data',
@@ -1582,7 +1582,7 @@ sub send_gcode {
         Content => [
             # OctoPrint doesn't like Windows paths so we use basename()
             # Also, since we need to read from filesystem we process it through encode_path()
-            file => [ $path, basename($path) ],
+            file => [ $enc_path, basename($enc_path) ],
         ],
     );
     
@@ -1603,7 +1603,7 @@ sub export_stl {
     return if !@{$self->{objects}};
         
     my $output_file = $self->_get_export_file('STL') or return;
-    $self->{model}->store_stl(Slic3r::encode_path($output_file), 1);
+    $self->{model}->store_stl($output_file, 1);
     $self->statusbar->SetStatusText("STL file exported to $output_file");
 }
 
@@ -1644,7 +1644,7 @@ sub export_object_stl {
     my $model_object = $self->{model}->objects->[$obj_idx];
         
     my $output_file = $self->_get_export_file('STL') or return;
-    $model_object->mesh->write_binary(Slic3r::encode_path($output_file));
+    $model_object->mesh->write_binary($output_file);
     $self->statusbar->SetStatusText("STL file exported to $output_file");
 }
 
@@ -1654,7 +1654,7 @@ sub export_amf {
     return if !@{$self->{objects}};
         
     my $output_file = $self->_get_export_file('AMF') or return;
-    $self->{model}->store_amf(Slic3r::encode_path($output_file));
+    $self->{model}->store_amf($output_file);
     $self->statusbar->SetStatusText("AMF file exported to $output_file");
 }
 
@@ -1674,7 +1674,7 @@ sub _get_export_file {
             $dlg->Destroy;
             return undef;
         }
-        $output_file = Slic3r::decode_path($dlg->GetPath);
+        $output_file = $dlg->GetPath;
         $dlg->Destroy;
     }
     return $output_file;
diff --git a/lib/Slic3r/GUI/Tab.pm b/lib/Slic3r/GUI/Tab.pm
index 08b44ef1e..33b7a7752 100644
--- a/lib/Slic3r/GUI/Tab.pm
+++ b/lib/Slic3r/GUI/Tab.pm
@@ -112,8 +112,9 @@ sub new {
         my $res = Wx::MessageDialog->new($self, "Are you sure you want to delete the selected preset?", 'Delete Preset', wxYES_NO | wxNO_DEFAULT | wxICON_QUESTION)->ShowModal;
         return unless $res == wxID_YES;
         # Delete the file.
-        my $path = Slic3r::encode_path($self->{presets}[$i]->file);
-        if (-e $path && ! unlink $path) {
+        my $path = $self->{presets}[$i]->file;
+        my $enc_path = Slic3r::encode_path($path);
+        if (-e $enc_path && ! unlink $enc_path) {
             # Cannot delete the file, therefore the item will not be removed from the selection.
             Slic3r::GUI::show_error($self, "Cannot delete file $path : $!");
             return;
@@ -255,7 +256,7 @@ sub select_preset {
 sub select_preset_by_name {
     my ($self, $name) = @_;
     
-    $name = Unicode::Normalize::NFC($name);
+    $name = Slic3r::normalize_utf8_nfc($name);
     $self->select_preset(first { $self->{presets}[$_]->name eq $name } 0 .. $#{$self->{presets}});
 }
 
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 0c0bc4b0e..3db1b0b43 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -75,21 +75,9 @@ sub export_gcode {
     # output everything to a G-code file
     my $output_file = $self->output_filepath($params{output_file} // '');
     $self->status_cb->(90, "Exporting G-code" . ($output_file ? " to $output_file" : ""));
-    
-    {
-        # open output gcode file if we weren't supplied a file-handle
-        my $tempfile = "$output_file.tmp";
-        my $gcode    = Slic3r::GCode->new();
-        my $result   = $gcode->do_export($self, Slic3r::encode_path($tempfile));
-        die $result . "\n" if ($result ne '');
-        my $i;
-        for ($i = 0; $i < 5; $i += 1)  {
-            last if (rename Slic3r::encode_path($tempfile), Slic3r::encode_path($output_file));
-            # Wait for 1/4 seconds and try to rename once again.
-            select(undef, undef, undef, 0.25);
-        }
-        Slic3r::debugf "Failed to remove the output G-code file from $tempfile to $output_file. Is $tempfile locked?\n" if ($i == 5);
-    }
+
+    die "G-code export to " . $output_file . " failed\n" 
+        if ! Slic3r::GCode->new->do_export($self, $output_file);
     
     # run post-processing scripts
     if (@{$self->config->post_process}) {
diff --git a/slic3r.pl b/slic3r.pl
index 26a7f51d3..1d3807a6c 100755
--- a/slic3r.pl
+++ b/slic3r.pl
@@ -18,6 +18,9 @@ use Time::HiRes qw(gettimeofday tv_interval);
 $|++;
 binmode STDOUT, ':utf8';
 
+# Convert all parameters from the local code page to utf8 on Windows.
+@ARGV = map Slic3r::decode_path($_), @ARGV if $^O eq 'MSWin32';
+
 our %opt = ();
 my %cli_options = ();
 {
@@ -65,7 +68,6 @@ my %cli_options = ();
 my @external_configs = ();
 if ($opt{load}) {
     foreach my $configfile (@{$opt{load}}) {
-        $configfile = Slic3r::decode_path($configfile);
         if (-e $configfile) {
             push @external_configs, Slic3r::Config->load($configfile);
         } elsif (-e "$FindBin::Bin/$configfile") {
@@ -102,7 +104,7 @@ 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::datadir       = $opt{datadir} // '';
         $Slic3r::GUI::no_controller = $opt{no_controller};
         $Slic3r::GUI::no_plater     = $opt{no_plater};
         $Slic3r::GUI::autosave      = $opt{autosave};
@@ -111,7 +113,7 @@ if ((!@ARGV || $opt{gui}) && !$opt{save} && eval "require Slic3r::GUI; 1") {
     setlocale(LC_NUMERIC, 'C');
     $gui->{mainframe}->load_config_file($_) for @{$opt{load}};
     $gui->{mainframe}->load_config($cli_config);
-    my @input_files = map Slic3r::decode_path($_), @ARGV;
+    my @input_files = @ARGV;
     $gui->{mainframe}{plater}->load_files(\@input_files) unless $opt{no_plater};
     $gui->MainLoop;
     exit;
@@ -123,7 +125,6 @@ if (@ARGV) {  # slicing from command line
     
     if ($opt{repair}) {
         foreach my $file (@ARGV) {
-            $file = Slic3r::decode_path($file);
             die "Repair is currently supported only on STL files\n"
                 if $file !~ /\.[sS][tT][lL]$/;
             
@@ -139,7 +140,6 @@ if (@ARGV) {  # slicing from command line
     
     if ($opt{cut}) {
         foreach my $file (@ARGV) {
-            $file = Slic3r::decode_path($file);
             my $model = Slic3r::Model->read_from_file($file);
             my $mesh = $model->mesh;
             $mesh->translate(0, 0, -$mesh->bounding_box->z_min);
@@ -158,7 +158,6 @@ if (@ARGV) {  # slicing from command line
     
     if ($opt{split}) {
         foreach my $file (@ARGV) {
-            $file = Slic3r::decode_path($file);
             my $model = Slic3r::Model->read_from_file($file);
             my $mesh = $model->mesh;
             $mesh->repair;
@@ -167,14 +166,13 @@ if (@ARGV) {  # slicing from command line
             foreach my $new_mesh (@{$mesh->split}) {
                 my $output_file = sprintf '%s_%02d.stl', $file, ++$part_count;
                 printf "Writing to %s\n", basename($output_file);
-                $new_mesh->write_binary(Slic3r::encode_path($output_file));
+                $new_mesh->write_binary($output_file);
             }
         }
         exit;
     }
     
     while (my $input_file = shift @ARGV) {
-        $input_file = Slic3r::decode_path($input_file);
         my $model;
         if ($opt{merge}) {
             my @models = map Slic3r::Model->read_from_file($_), $input_file, (splice @ARGV, 0);
diff --git a/utils/amf-to-stl.pl b/utils/amf-to-stl.pl
index f49af94eb..2648ba25d 100755
--- a/utils/amf-to-stl.pl
+++ b/utils/amf-to-stl.pl
@@ -14,6 +14,9 @@ use Getopt::Long qw(:config no_auto_abbrev);
 use Slic3r;
 $|++;
 
+# Convert all parameters from the local code page to utf8 on Windows.
+@ARGV = map Slic3r::decode_path($_), @ARGV if $^O eq 'MSWin32';
+
 my %opt = ();
 {
     my %options = (
@@ -25,12 +28,12 @@ my %opt = ();
 }
 
 {
-    my $model = Slic3r::Model->load_amf(Slic3r::encode_path($ARGV[0]));
+    my $model = Slic3r::Model->load_amf($ARGV[0]);
     my $output_file = $ARGV[0];
     $output_file =~ s/\.[aA][mM][fF](?:\.[xX][mM][lL])?$/\.stl/;
     
     printf "Writing to %s\n", basename($output_file);
-    $model->store_stl(Slic3r::encode_path($output_file), binary => !$opt{ascii});
+    $model->store_stl($output_file, binary => !$opt{ascii});
 }
 
 
diff --git a/utils/dump-stl.pl b/utils/dump-stl.pl
index 12746feab..0f459ffb1 100644
--- a/utils/dump-stl.pl
+++ b/utils/dump-stl.pl
@@ -18,7 +18,7 @@ $|++;
 $ARGV[0] or usage(1);
 
 if (-e $ARGV[0]) {
-    my $model = Slic3r::Model->load_stl(Slic3r::encode_path($ARGV[0]), basename($ARGV[0]));
+    my $model = Slic3r::Model->load_stl($ARGV[0], basename($ARGV[0]));
     $model->objects->[0]->add_instance(offset => Slic3r::Pointf->new(0,0));
     my $mesh = $model->mesh;
     $mesh->repair;
@@ -27,7 +27,7 @@ if (-e $ARGV[0]) {
     exit 0;
 } elsif ((my $model = Slic3r::Test::model($ARGV[0]))) {
     $ARGV[1] or die "Missing writeable destination as second argument\n";
-    $model->store_stl(Slic3r::encode_path($ARGV[1]), 1);
+    $model->store_stl($ARGV[1], 1);
     printf "Model $ARGV[0] written to $ARGV[1]\n";
     exit 0;
 } else {
diff --git a/utils/split_stl.pl b/utils/split_stl.pl
index ac890fc3e..fffc57665 100755
--- a/utils/split_stl.pl
+++ b/utils/split_stl.pl
@@ -25,7 +25,7 @@ my %opt = ();
 }
 
 {
-    my $model = Slic3r::Model->load_stl(Slic3r::encode_path($ARGV[0]), basename($ARGV[0]));
+    my $model = Slic3r::Model->load_stl($ARGV[0], basename($ARGV[0]));
     my $basename = $ARGV[0];
     $basename =~ s/\.[sS][tT][lL]$//;
     
@@ -43,7 +43,7 @@ my %opt = ();
         
         my $output_file = sprintf '%s_%02d.stl', $basename, ++$part_count;
         printf "Writing to %s\n", basename($output_file);
-        $new_model->store_stl(Slic3r::encode_path($output_file), !$opt{ascii});
+        $new_model->store_stl($output_file, !$opt{ascii});
     }
 }
 
diff --git a/utils/stl-to-amf.pl b/utils/stl-to-amf.pl
index d32e799aa..f0d537b04 100755
--- a/utils/stl-to-amf.pl
+++ b/utils/stl-to-amf.pl
@@ -25,7 +25,7 @@ my %opt = ();
 }
 
 {
-    my @models = map Slic3r::Model->load_stl(Slic3r::encode_path($_), basename($_)), @ARGV;
+    my @models = map Slic3r::Model->load_stl($_, basename($_)), @ARGV;
     my $output_file = $ARGV[0];
     $output_file =~ s/\.[sS][tT][lL]$/.amf.xml/;
     
@@ -53,7 +53,7 @@ my %opt = ();
     }
     
     printf "Writing to %s\n", basename($output_file);
-    $new_model->store_amf(Slic3r::encode_path($output_file));
+    $new_model->store_amf($output_file);
 }
 
 
diff --git a/xs/Build.PL b/xs/Build.PL
index ff91114f0..7f2a03926 100644
--- a/xs/Build.PL
+++ b/xs/Build.PL
@@ -129,11 +129,11 @@ if (defined $ENV{BOOST_LIBRARYDIR}) {
 
 # In order to generate the -l switches we need to know how Boost libraries are named
 my $have_boost = 0;
-my @boost_libraries = qw(system thread filesystem log);  # we need these
+my @boost_libraries = qw(system thread filesystem locale log);  # we need these
 
 if (!$ENV{SLIC3R_STATIC}) {
     # Dynamic linking of boost libraries.
-    push @cflags, qw(-DBOOST_LOG_DYN_LINK);
+    push @cflags, qw(-DBOOST_LOG_DYN_LINK -DBOOST_LOCALE_DYN_LINK);
     if (! $mswin) {
         # Check without explicit lib path (works on Linux and OSX).
         $have_boost = 1
@@ -193,10 +193,10 @@ path through the BOOST_DIR environment variable:
 Or you may specify BOOST_INCLUDEDIR and BOOST_LIBRARYDIR separatly, which
 is handy, if you have built Boost libraries with mutliple settings.
 
-Following boost libraries are needed by Slic3r Prusa Edition: system, filesystem, thread, log.
+Following boost libraries are needed by Slic3r Prusa Edition: system, filesystem, thread, locale, log.
 
 On Debian, you need to run
-sudo apt-get install libboost-thread-dev libboost-system-dev libboost-filesystem-dev libboost-log-dev
+sudo apt-get install libboost-thread-dev libboost-system-dev libboost-filesystem-dev libboost-locale-dev libboost-log-dev
 
 EOF
 
diff --git a/xs/MANIFEST b/xs/MANIFEST
index 028556906..9148b3e08 100644
--- a/xs/MANIFEST
+++ b/xs/MANIFEST
@@ -1,13 +1,13 @@
 Build.PL
 lib/Slic3r/XS.pm
 MANIFEST			This list of files
-src/admesh/connect.c
-src/admesh/normals.c
-src/admesh/shared.c
+src/admesh/connect.cpp
+src/admesh/normals.cpp
+src/admesh/shared.cpp
 src/admesh/stl.h
-src/admesh/stl_io.c
-src/admesh/stlinit.c
-src/admesh/util.c
+src/admesh/stl_io.cpp
+src/admesh/stlinit.cpp
+src/admesh/util.cpp
 src/boost/nowide/args.hpp
 src/boost/nowide/cenv.hpp
 src/boost/nowide/config.hpp
diff --git a/xs/src/admesh/connect.c b/xs/src/admesh/connect.cpp
index e9129d007..e9129d007 100644
--- a/xs/src/admesh/connect.c
+++ b/xs/src/admesh/connect.cpp
diff --git a/xs/src/admesh/normals.c b/xs/src/admesh/normals.cpp
index 2832899fa..28b1c47b0 100644
--- a/xs/src/admesh/normals.c
+++ b/xs/src/admesh/normals.cpp
@@ -27,9 +27,13 @@
 
 #include "stl.h"
 
-static void stl_reverse_facet(stl_file *stl, int facet_num);
-static void stl_reverse_vector(float v[]);
-int stl_check_normal_vector(stl_file *stl, int facet_num, int normal_fix_flag);
+static void stl_reverse_vector(float v[]) {
+  v[0] *= -1;
+  v[1] *= -1;
+  v[2] *= -1;
+}
+
+static int stl_check_normal_vector(stl_file *stl, int facet_num, int normal_fix_flag);
 
 static void
 stl_reverse_facet(stl_file *stl, int facet_num) {
@@ -136,10 +140,8 @@ stl_fix_normal_directions(stl_file *stl) {
       /* Reverse the neighboring facets if necessary. */
       if(stl->neighbors_start[facet_num].which_vertex_not[j] > 2) {
         /* If the facet has a neighbor that is -1, it means that edge isn't shared by another facet */
-        if(stl->neighbors_start[facet_num].neighbor[j] != -1) {
-          stl_reverse_facet
-          (stl, stl->neighbors_start[facet_num].neighbor[j]);
-        }
+        if(stl->neighbors_start[facet_num].neighbor[j] != -1)
+          stl_reverse_facet(stl, stl->neighbors_start[facet_num].neighbor[j]);
       }
       /* If this edge of the facet is connected: */
       if(stl->neighbors_start[facet_num].neighbor[j] != -1) {
@@ -193,8 +195,7 @@ stl_fix_normal_directions(stl_file *stl) {
   free(norm_sw);
 }
 
-int
-stl_check_normal_vector(stl_file *stl, int facet_num, int normal_fix_flag) {
+static int stl_check_normal_vector(stl_file *stl, int facet_num, int normal_fix_flag) {
   /* Returns 0 if the normal is within tolerance */
   /* Returns 1 if the normal is not within tolerance, but direction is OK */
   /* Returns 2 if the normal is not within tolerance and backwards */
@@ -259,26 +260,17 @@ stl_check_normal_vector(stl_file *stl, int facet_num, int normal_fix_flag) {
   return 4;
 }
 
-static void
-stl_reverse_vector(float v[]) {
-  v[0] *= -1;
-  v[1] *= -1;
-  v[2] *= -1;
-}
-
-
-void
-stl_calculate_normal(float normal[], stl_facet *facet) {
-  float v1[3];
-  float v2[3];
-
-  v1[0] = facet->vertex[1].x - facet->vertex[0].x;
-  v1[1] = facet->vertex[1].y - facet->vertex[0].y;
-  v1[2] = facet->vertex[1].z - facet->vertex[0].z;
-  v2[0] = facet->vertex[2].x - facet->vertex[0].x;
-  v2[1] = facet->vertex[2].y - facet->vertex[0].y;
-  v2[2] = facet->vertex[2].z - facet->vertex[0].z;
-
+void stl_calculate_normal(float normal[], stl_facet *facet) {
+  float v1[3] = {
+    facet->vertex[1].x - facet->vertex[0].x,
+    facet->vertex[1].y - facet->vertex[0].y,
+    facet->vertex[1].z - facet->vertex[0].z
+  };
+  float v2[3] = {
+    facet->vertex[2].x - facet->vertex[0].x,
+    facet->vertex[2].y - facet->vertex[0].y,
+    facet->vertex[2].z - facet->vertex[0].z
+  };
   normal[0] = (float)((double)v1[1] * (double)v2[2]) - ((double)v1[2] * (double)v2[1]);
   normal[1] = (float)((double)v1[2] * (double)v2[0]) - ((double)v1[0] * (double)v2[2]);
   normal[2] = (float)((double)v1[0] * (double)v2[1]) - ((double)v1[1] * (double)v2[0]);
diff --git a/xs/src/admesh/shared.c b/xs/src/admesh/shared.cpp
index 56164e25f..8080f3574 100644
--- a/xs/src/admesh/shared.c
+++ b/xs/src/admesh/shared.cpp
@@ -23,6 +23,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <boost/nowide/cstdio.hpp>
+
 #include "stl.h"
 
 void
@@ -149,7 +151,7 @@ stl_write_off(stl_file *stl, char *file) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  fp = boost::nowide::fopen(file, "w");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -185,7 +187,7 @@ stl_write_vrml(stl_file *stl, char *file) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  fp = boost::nowide::fopen(file, "w");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -241,7 +243,7 @@ void stl_write_obj (stl_file *stl, char *file) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  fp = boost::nowide::fopen(file, "w");
   if (fp == NULL) {
     char* error_msg = (char*)malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
     sprintf(error_msg, "stl_write_ascii: Couldn't open %s for writing", file);
diff --git a/xs/src/admesh/stl.h b/xs/src/admesh/stl.h
index 139983632..82c860636 100644
--- a/xs/src/admesh/stl.h
+++ b/xs/src/admesh/stl.h
@@ -32,10 +32,6 @@
 #error "admesh works correctly on little endian machines only!"
 #endif
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #define STL_MAX(A,B) ((A)>(B)? (A):(B))
 #define STL_MIN(A,B) ((A)<(B)? (A):(B))
 #define ABS(X)  ((X) < 0 ? -(X) : (X))
@@ -223,8 +219,4 @@ extern void stl_clear_error(stl_file *stl);
 extern int stl_get_error(stl_file *stl);
 extern void stl_exit_on_error(stl_file *stl);
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif
diff --git a/xs/src/admesh/stl_io.c b/xs/src/admesh/stl_io.cpp
index 7d8e4eab8..f58d6b4f6 100644
--- a/xs/src/admesh/stl_io.c
+++ b/xs/src/admesh/stl_io.cpp
@@ -25,6 +25,8 @@
 #include "stl.h"
 #include "config.h"
 
+#include <boost/nowide/cstdio.hpp>
+
 #if !defined(SEEK_SET)
 #define SEEK_SET 0
 #define SEEK_CUR 1
@@ -126,13 +128,12 @@ Normals fixed         : %5d\n", stl->stats.normals_fixed);
 void
 stl_write_ascii(stl_file *stl, const char *file, const char *label) {
   int       i;
-  FILE      *fp;
   char      *error_msg;
 
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  FILE *fp = boost::nowide::fopen(file, "w");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -178,7 +179,7 @@ stl_print_neighbors(stl_file *stl, char *file) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  fp = boost::nowide::fopen(file, "w");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -212,7 +213,7 @@ stl_write_binary(stl_file *stl, const char *file, const char *label) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "wb");
+  fp = boost::nowide::fopen(file, "wb");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -292,7 +293,7 @@ stl_write_quad_object(stl_file *stl, char *file) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  fp = boost::nowide::fopen(file, "w");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -360,7 +361,7 @@ stl_write_dxf(stl_file *stl, char *file, char *label) {
   if (stl->error) return;
 
   /* Open the file */
-  fp = fopen(file, "w");
+  fp = boost::nowide::fopen(file, "w");
   if(fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
diff --git a/xs/src/admesh/stlinit.c b/xs/src/admesh/stlinit.cpp
index 13f1f43af..f5110d394 100644
--- a/xs/src/admesh/stlinit.c
+++ b/xs/src/admesh/stlinit.cpp
@@ -26,6 +26,8 @@
 #include <math.h>
 #include <assert.h>
 
+#include <boost/nowide/cstdio.hpp>
+
 #include "stl.h"
 
 #ifndef SEEK_SET
@@ -62,7 +64,7 @@ stl_count_facets(stl_file *stl, const char *file) {
   if (stl->error) return;
 
   /* Open the file in binary mode first */
-  stl->fp = fopen(file, "rb");
+  stl->fp = boost::nowide::fopen(file, "rb");
   if(stl->fp == NULL) {
     error_msg = (char*)
                 malloc(81 + strlen(file)); /* Allow 80 chars+file size for message */
@@ -121,7 +123,7 @@ stl_count_facets(stl_file *stl, const char *file) {
     /* Reopen the file in text mode (for getting correct newlines on Windows) */
     // fix to silence a warning about unused return value.
     // obviously if it fails we have problems....
-    stl->fp = freopen(file, "r", stl->fp);
+    stl->fp = boost::nowide::freopen(file, "r", stl->fp);
 
     // do another null check to be safe
     if(stl->fp == NULL) {
diff --git a/xs/src/admesh/util.c b/xs/src/admesh/util.cpp
index cabb8a778..b0c31469d 100644
--- a/xs/src/admesh/util.c
+++ b/xs/src/admesh/util.cpp
@@ -186,7 +186,7 @@ static void calculate_normals(stl_file *stl) {
 }
 
 void stl_transform(stl_file *stl, float *trafo3x4) {
-  int i_face, i_vertex, i, j;
+  int i_face, i_vertex;
   if (stl->error)
     return;
   for (i_face = 0; i_face < stl->stats.number_of_facets; ++ i_face) {
@@ -404,7 +404,7 @@ static float get_volume(stl_file *stl) {
     n = stl->facet_start[i].normal;
     height = (n.x * p.x) + (n.y * p.y) + (n.z * p.z);
     area = get_area(&stl->facet_start[i]);
-    volume += (area * height) / 3.0;
+    volume += (area * height) / 3.0f;
   }
   return volume;
 }
diff --git a/xs/src/libslic3r/Format/AMF.cpp b/xs/src/libslic3r/Format/AMF.cpp
index 9a9047eac..b8abf038b 100644
--- a/xs/src/libslic3r/Format/AMF.cpp
+++ b/xs/src/libslic3r/Format/AMF.cpp
@@ -3,6 +3,8 @@
 #include <string>
 #include <expat/expat.h>
 
+#include <boost/nowide/cstdio.hpp>
+
 #include "../libslic3r.h"
 #include "../Model.hpp"
 #include "AMF.hpp"
@@ -480,7 +482,7 @@ bool load_amf(const char *path, Model *model)
         return false;
     }
 
-    FILE *pFile = ::fopen(path, "rt");
+    FILE *pFile = boost::nowide::fopen(path, "rt");
     if (pFile == nullptr) {
         printf("Cannot open file %s\n", path);
         return false;
@@ -522,7 +524,7 @@ bool load_amf(const char *path, Model *model)
 
 bool store_amf(const char *path, Model *model)
 {
-    FILE *file = ::fopen(path, "wb");
+    FILE *file = boost::nowide::fopen(path, "wb");
     if (file == nullptr)
         return false;
 
diff --git a/xs/src/libslic3r/Format/PRUS.cpp b/xs/src/libslic3r/Format/PRUS.cpp
index 6b686d6ea..b7ef33774 100644
--- a/xs/src/libslic3r/Format/PRUS.cpp
+++ b/xs/src/libslic3r/Format/PRUS.cpp
@@ -2,6 +2,8 @@
 
 #include <string.h>
 
+#include <boost/nowide/convert.hpp>
+
 #include <wx/string.h>
 #include <wx/wfstream.h>
 #include <wx/zipstrm.h>
@@ -119,7 +121,14 @@ bool load_prus(const char *path, Model *model)
 {
     // To receive the content of the zipped 'scene.xml' file.
     std::vector<char>           scene_xml_data;
-    wxFFileInputStream          in(path);
+    wxFFileInputStream          in(
+#ifdef WIN32
+        // On Windows, convert to a 16bit unicode string.
+        boost::nowide::widen(path).c_str()
+#else
+        path
+#endif
+        );
     wxZipInputStream            zip(in);
     std::unique_ptr<wxZipEntry> entry;
     size_t                      num_models = 0;
diff --git a/xs/src/libslic3r/Format/objparser.cpp b/xs/src/libslic3r/Format/objparser.cpp
index d8b86b703..88dfae695 100644
--- a/xs/src/libslic3r/Format/objparser.cpp
+++ b/xs/src/libslic3r/Format/objparser.cpp
@@ -1,6 +1,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <boost/nowide/cstdio.hpp>
+
 #include "objparser.hpp"
 
 namespace ObjParser {
@@ -318,7 +320,7 @@ static bool obj_parseline(const char *line, ObjData &data)
 
 bool objparse(const char *path, ObjData &data)
 {
-	FILE *pFile = ::fopen(path, "rt");
+	FILE *pFile = boost::nowide::fopen(path, "rt");
 	if (pFile == 0)
 		return false;
 
@@ -446,7 +448,7 @@ bool loadvectornameidx(FILE *pFile, std::vector<T> &v)
 
 bool objbinsave(const char *path, const ObjData &data)
 {
-	FILE *pFile = ::fopen(path, "wb");
+	FILE *pFile = boost::nowide::fopen(path, "wb");
 	if (pFile == 0)
 		return false;
 
@@ -471,7 +473,7 @@ bool objbinsave(const char *path, const ObjData &data)
 
 bool objbinload(const char *path, ObjData &data)
 {
-	FILE *pFile = ::fopen(path, "rb");
+	FILE *pFile = boost::nowide::fopen(path, "rb");
 	if (pFile == 0)
 		return false;
 
diff --git a/xs/src/libslic3r/GCode.cpp b/xs/src/libslic3r/GCode.cpp
index 5acda3a98..699621974 100644
--- a/xs/src/libslic3r/GCode.cpp
+++ b/xs/src/libslic3r/GCode.cpp
@@ -13,6 +13,10 @@
 #include <boost/date_time/local_time/local_time.hpp>
 #include <boost/foreach.hpp>
 
+#include <boost/nowide/iostream.hpp>
+#include <boost/nowide/cstdio.hpp>
+#include <boost/nowide/cstdlib.hpp>
+
 #include "SVG.hpp"
 
 #if 0
@@ -306,7 +310,33 @@ std::vector<std::pair<coordf_t, std::vector<GCode::LayerToPrint>>> GCode::collec
     return layers_to_print;
 }
 
-bool GCode::do_export(FILE *file, Print &print)
+bool GCode::do_export(Print *print, const char *path)
+{
+    // Remove the old g-code if it exists.
+    boost::nowide::remove(path);
+
+    std::string path_tmp(path);
+    path_tmp += ".tmp";
+
+    FILE *file = boost::nowide::fopen(path_tmp.c_str(), "wb");
+    if (file == nullptr)
+        return false;
+
+    bool result = this->_do_export(*print, file);
+    fclose(file);
+
+    if (result && boost::nowide::rename(path_tmp.c_str(), path) != 0) {
+        boost::nowide::cerr << "Failed to remove the output G-code file from " << path_tmp << " to " << path
+            << ". Is " << path_tmp << " locked?" << std::endl;
+        result = false;
+    }
+
+    if (! result)
+        boost::nowide::remove(path_tmp.c_str());
+    return result;
+}
+
+bool GCode::_do_export(Print &print, FILE *file)
 {
     // How many times will be change_layer() called?
     // change_layer() in turn increments the progress bar status.
diff --git a/xs/src/libslic3r/GCode.hpp b/xs/src/libslic3r/GCode.hpp
index 51ab5eb84..ac0af3f2c 100644
--- a/xs/src/libslic3r/GCode.hpp
+++ b/xs/src/libslic3r/GCode.hpp
@@ -126,7 +126,7 @@ public:
         {}
     ~GCode() {}
 
-    bool            do_export(FILE *file, Print &print);
+    bool            do_export(Print *print, const char *path);
 
     // Exported for the helper classes (OozePrevention, Wipe) and for the Perl binding for unit tests.
     const Pointf&   origin() const { return m_origin; }
@@ -146,6 +146,8 @@ public:
     void            apply_print_config(const PrintConfig &print_config);
 
 protected:
+    bool            _do_export(Print &print, FILE *file);
+
     // Object and support extrusions of the same PrintObject at the same print_z.
     struct LayerToPrint
     {
diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index 5d0de1576..455469f8a 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -10,6 +10,7 @@
 
 #include <boost/algorithm/string/predicate.hpp>
 #include <boost/filesystem.hpp>
+#include <boost/nowide/iostream.hpp>
 
 namespace Slic3r {
 
@@ -739,7 +740,7 @@ void ModelObject::print_info() const
 {
     using namespace std;
     cout << fixed;
-    cout << "[" << boost::filesystem::path(this->input_file).filename().string() << "]" << endl;
+    boost::nowide::cout << "[" << boost::filesystem::path(this->input_file).filename().string() << "]" << endl;
     
     TriangleMesh mesh = this->raw_mesh();
     mesh.check_topology();
diff --git a/xs/src/libslic3r/SVG.cpp b/xs/src/libslic3r/SVG.cpp
index b8580fd5e..c94db8e74 100644
--- a/xs/src/libslic3r/SVG.cpp
+++ b/xs/src/libslic3r/SVG.cpp
@@ -1,6 +1,8 @@
 #include "SVG.hpp"
 #include <iostream>
 
+#include <boost/nowide/cstdio.hpp>
+
 #define COORD(x) ((float)unscale((x))*10)
 
 namespace Slic3r {
@@ -8,7 +10,7 @@ namespace Slic3r {
 bool SVG::open(const char* afilename)
 {
     this->filename = afilename;
-    this->f = fopen(afilename, "w");
+    this->f = boost::nowide::fopen(afilename, "w");
     if (this->f == NULL)
         return false;
     fprintf(this->f,
@@ -27,7 +29,7 @@ bool SVG::open(const char* afilename, const BoundingBox &bbox, const coord_t bbo
     this->filename = afilename;
     this->origin   = bbox.min - Point(bbox_offset, bbox_offset);
     this->flipY    = aflipY;
-    this->f        = ::fopen(afilename, "w");
+    this->f        = boost::nowide::fopen(afilename, "w");
     if (f == NULL)
         return false;
     float w = COORD(bbox.max.x - bbox.min.x + 2 * bbox_offset);
diff --git a/xs/src/libslic3r/Utils.hpp b/xs/src/libslic3r/Utils.hpp
index 0b6b87d28..45d1f2c51 100644
--- a/xs/src/libslic3r/Utils.hpp
+++ b/xs/src/libslic3r/Utils.hpp
@@ -6,6 +6,10 @@ namespace Slic3r {
 extern void set_logging_level(unsigned int level);
 extern void trace(unsigned int level, const char *message);
 
+extern std::string encode_path(const char *src);
+extern std::string decode_path(const char *src);
+extern std::string normalize_utf8_nfc(const char *src);
+
 // Compute the next highest power of 2 of 32-bit v
 // http://graphics.stanford.edu/~seander/bithacks.html
 template<typename T>
diff --git a/xs/src/libslic3r/utils.cpp b/xs/src/libslic3r/utils.cpp
index 50db6f300..ea34fb18c 100644
--- a/xs/src/libslic3r/utils.cpp
+++ b/xs/src/libslic3r/utils.cpp
@@ -1,7 +1,21 @@
+#include <locale>
+
 #include <boost/log/core.hpp>
 #include <boost/log/trivial.hpp>
 #include <boost/log/expressions.hpp>
 
+#include <boost/locale.hpp>
+
+#include <boost/nowide/integration/filesystem.hpp>
+#include <boost/nowide/convert.hpp>
+
+#ifdef WIN32
+extern "C" {
+__declspec(dllimport) int WideCharToMultiByte(unsigned int, unsigned long, wchar_t const *, int, char *, int, char const *, int *);
+__declspec(dllimport) int MultiByteToWideChar(unsigned int, unsigned long, char const *, int, wchar_t *, int);
+}
+#endif /* WIN32 */
+
 namespace Slic3r {
 
 static boost::log::trivial::severity_level logSeverity = boost::log::trivial::error;
@@ -30,9 +44,13 @@ void set_logging_level(unsigned int level)
 }
 
 // Force set_logging_level(<=error) after loading of the DLL.
-static struct SetLoggingLevelOnInit {
-    SetLoggingLevelOnInit() { set_logging_level(1); }
-} g_SetLoggingLevelOnInit;
+// Switch boost::filesystem to utf8.
+static struct RunOnInit {
+    RunOnInit() { 
+        boost::nowide::nowide_filesystem();
+        set_logging_level(1);
+    }
+} g_RunOnInit;
 
 void trace(unsigned int level, const char *message)
 {
@@ -56,6 +74,46 @@ void trace(unsigned int level, const char *message)
         (::boost::log::keywords::severity = severity)) << message;
 }
 
+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(), const_cast<char*>(str_dst.data()), size_needed, nullptr, nullptr);
+    return str_dst;
+#else /* WIN32 */
+    return src;
+#endif /* WIN32 */
+}
+
+std::string decode_path(const char *src)
+{  
+#ifdef WIN32
+    int len = 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, const_cast<wchar_t*>(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("en_US.UTF-8");
+    return boost::locale::normalize(src, boost::locale::norm_nfc, locale_utf8);
+}
+
 } // namespace Slic3r
 
 #ifdef SLIC3R_HAS_BROKEN_CROAK
diff --git a/xs/xsp/GCode.xsp b/xs/xsp/GCode.xsp
index 9104e481a..ea54fd3a7 100644
--- a/xs/xsp/GCode.xsp
+++ b/xs/xsp/GCode.xsp
@@ -17,17 +17,7 @@
 %name{Slic3r::GCode} class GCode {
     GCode();
     ~GCode();
-    std::string do_export(Print *print, const char *path)
-        %code{%
-            FILE *file = fopen(path, "wb");
-            if (file == nullptr) {
-                RETVAL = std::string("Failed to open ") + path + " for writing.";
-            } else {
-                THIS->do_export(file, *print);
-                fclose(file);
-                RETVAL = std::string();
-            }
-        %};
+    std::string do_export(Print *print, const char *path);
 
     Ref<Pointf> origin()
         %code{% RETVAL = &(THIS->origin()); %};
diff --git a/xs/xsp/XS.xsp b/xs/xsp/XS.xsp
index 8389e2d99..6ba6817c1 100644
--- a/xs/xsp/XS.xsp
+++ b/xs/xsp/XS.xsp
@@ -48,6 +48,24 @@ trace(level, message)
     CODE:
         Slic3r::trace(level, message);
 
+std::string
+encode_path(src)
+    const char *src;
+    CODE:
+        Slic3r::encode_path(src);
+
+std::string
+decode_path(src)
+    const char *src;
+    CODE:
+        Slic3r::decode_path(src);
+
+std::string
+normalize_utf8_nfc(src)
+    const char *src;
+    CODE:
+        Slic3r::normalize_utf8_nfc(src);
+
 void
 xspp_test_croak_hangs_on_strawberry()
     CODE: