diff --git a/lib/Slic3r/GUI.pm b/lib/Slic3r/GUI.pm
index f0a8adc5..1e368d9f 100644
--- a/lib/Slic3r/GUI.pm
+++ b/lib/Slic3r/GUI.pm
@@ -8,6 +8,7 @@ use FindBin;
 use Slic3r::GUI::AboutDialog;
 use Slic3r::GUI::ConfigWizard;
 use Slic3r::GUI::Plater;
+use Slic3r::GUI::Plater::2D;
 use Slic3r::GUI::Plater::ObjectPartsPanel;
 use Slic3r::GUI::Plater::ObjectCutDialog;
 use Slic3r::GUI::Plater::ObjectPreviewDialog;
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index a2750193..e24e6014 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -4,11 +4,10 @@ use warnings;
 use utf8;
 
 use File::Basename qw(basename dirname);
-use List::Util qw(max sum first);
-use Slic3r::Geometry::Clipper qw(offset JT_ROUND);
-use Slic3r::Geometry qw(X Y Z MIN MAX convex_hull scale unscale);
+use List::Util qw(sum first);
+use Slic3r::Geometry qw(X Y Z MIN MAX scale unscale);
 use threads::shared qw(shared_clone);
-use Wx qw(:bitmap :brush :button :cursor :dialog :filedialog :font :keycode :icon :id :listctrl :misc :panel :pen :sizer :toolbar :window);
+use Wx qw(:button :cursor :dialog :filedialog :keycode :icon :font :id :listctrl :misc :panel :sizer :toolbar :window);
 use Wx::Event qw(EVT_BUTTON EVT_COMMAND EVT_KEY_DOWN EVT_LIST_ITEM_ACTIVATED EVT_LIST_ITEM_DESELECTED EVT_LIST_ITEM_SELECTED EVT_MOUSE_EVENTS EVT_PAINT EVT_TOOL EVT_CHOICE);
 use base 'Wx::Panel';
 
@@ -36,9 +35,6 @@ our $EXPORT_COMPLETED_EVENT  : shared = Wx::NewEventType;
 our $EXPORT_FAILED_EVENT     : shared = Wx::NewEventType;
 
 use constant CANVAS_SIZE => [335,335];
-use constant CANVAS_TEXT => join('-', +(localtime)[3,4]) eq '13-8'
-    ? 'What do you want to print today? ™' # Sept. 13, 2006. The first part ever printed by a RepRap to make another RepRap.
-    : 'Drag your objects here';
 use constant FILAMENT_CHOOSERS_SPACING => 3;
 
 my $PreventListEvents = 0;
@@ -54,19 +50,17 @@ sub new {
     $self->{print} = Slic3r::Print->new;
     $self->{objects} = [];
     
-    $self->{canvas} = Wx::Panel->new($self, -1, wxDefaultPosition, CANVAS_SIZE, wxTAB_TRAVERSAL);
-    $self->{canvas}->SetBackgroundColour(Wx::wxWHITE);
-    EVT_PAINT($self->{canvas}, \&repaint);
-    EVT_MOUSE_EVENTS($self->{canvas}, \&mouse_event);
-    
-    $self->{objects_brush} = Wx::Brush->new(Wx::Colour->new(210,210,210), wxSOLID);
-    $self->{selected_brush} = Wx::Brush->new(Wx::Colour->new(255,128,128), wxSOLID);
-    $self->{dragged_brush} = Wx::Brush->new(Wx::Colour->new(128,128,255), wxSOLID);
-    $self->{transparent_brush} = Wx::Brush->new(Wx::Colour->new(0,0,0), wxTRANSPARENT);
-    $self->{grid_pen} = Wx::Pen->new(Wx::Colour->new(230,230,230), 1, wxSOLID);
-    $self->{print_center_pen} = Wx::Pen->new(Wx::Colour->new(200,200,200), 1, wxSOLID);
-    $self->{clearance_pen} = Wx::Pen->new(Wx::Colour->new(0,0,200), 1, wxSOLID);
-    $self->{skirt_pen} = Wx::Pen->new(Wx::Colour->new(150,150,150), 1, wxSOLID);
+    $self->{canvas} = Slic3r::GUI::Plater::2D->new($self, CANVAS_SIZE, $self->{objects}, $self->{model}, $self->{config});
+    $self->{canvas}->on_select_object(sub {
+        my ($obj_idx) = @_;
+        $self->select_object($obj_idx);
+    });
+    $self->{canvas}->on_double_click(sub {
+        $self->object_cut_dialog if $self->selected_object;
+    });
+    $self->{canvas}->on_instance_moved(sub {
+        $self->update;
+    });
     
     # toolbar for object manipulation
     if (!&Wx::wxMSW) {
@@ -224,7 +218,7 @@ sub new {
         $self->on_export_failed;
     });
     
-    $self->_update_bed_size;
+    $self->{canvas}->update_bed_size;
     $self->update;
     
     {
@@ -597,8 +591,8 @@ sub arrange {
     
     # get the bounding box of the model area shown in the viewport
     my $bb = Slic3r::Geometry::BoundingBox->new_from_points([
-        Slic3r::Point->new(@{ $self->point_to_model_units([0,0]) }),
-        Slic3r::Point->new(@{ $self->point_to_model_units(CANVAS_SIZE) }),
+        Slic3r::Point->new(@{ $self->{canvas}->point_to_model_units([0,0]) }),
+        Slic3r::Point->new(@{ $self->{canvas}->point_to_model_units(CANVAS_SIZE) }),
     ]);
     
     eval {
@@ -896,14 +890,6 @@ sub on_thumbnail_made {
     $self->{canvas}->Refresh;
 }
 
-sub clean_instance_thumbnails {
-    my ($self) = @_;
-    
-    foreach my $object (@{ $self->{objects} }) {
-        @{ $object->instance_thumbnails } = ();
-    }
-}
-
 # this method gets called whenever print center is changed or the objects' bounding box changes
 # (i.e. when an object is added/removed/moved/rotated/scaled)
 sub update {
@@ -947,184 +933,14 @@ sub on_config_change {
         $self->Layout;
     } elsif ($self->{config}->has($opt_key)) {
         $self->{config}->set($opt_key, $value);
-        $self->_update_bed_size if $opt_key eq 'bed_size';
+        if ($opt_key eq 'bed_size') {
+            $self->{canvas}->update_bed_size;
+            $self->update;
+        }
         $self->update if $opt_key eq 'print_center';
     }
 }
 
-sub _update_bed_size {
-    my $self = shift;
-    
-    # supposing the preview canvas is square, calculate the scaling factor
-    # to constrain print bed area inside preview
-    # when the canvas is not rendered yet, its GetSize() method returns 0,0
-    # scaling_factor is expressed in pixel / mm
-    $self->{scaling_factor} = CANVAS_SIZE->[X] / max(@{ $self->{config}->bed_size });
-    $self->update;
-}
-
-# this is called on the canvas
-sub repaint {
-    my ($self, $event) = @_;
-    my $parent = $self->GetParent;
-    
-    my $dc = Wx::PaintDC->new($self);
-    my $size = $self->GetSize;
-    my @size = ($size->GetWidth, $size->GetHeight);
-    
-    # draw grid
-    $dc->SetPen($parent->{grid_pen});
-    my $step = 10 * $parent->{scaling_factor};
-    for (my $x = $step; $x <= $size[X]; $x += $step) {
-        $dc->DrawLine($x, 0, $x, $size[Y]);
-    }
-    for (my $y = $step; $y <= $size[Y]; $y += $step) {
-        $dc->DrawLine(0, $y, $size[X], $y);
-    }
-    
-    # draw print center
-    if (@{$parent->{objects}}) {
-        $dc->SetPen($parent->{print_center_pen});
-        $dc->DrawLine($size[X]/2, 0, $size[X]/2, $size[Y]);
-        $dc->DrawLine(0, $size[Y]/2, $size[X], $size[Y]/2);
-        $dc->SetTextForeground(Wx::Colour->new(0,0,0));
-        $dc->SetFont(Wx::Font->new(10, wxDEFAULT, wxNORMAL, wxNORMAL));
-        $dc->DrawLabel("X = " . $parent->{config}->print_center->[X], Wx::Rect->new(0, 0, $self->GetSize->GetWidth, $self->GetSize->GetHeight), wxALIGN_CENTER_HORIZONTAL | wxALIGN_BOTTOM);
-        $dc->DrawRotatedText("Y = " . $parent->{config}->print_center->[Y], 0, $size[Y]/2+15, 90);
-    }
-    
-    # draw frame
-    if (0) {
-        $dc->SetPen(wxBLACK_PEN);
-        $dc->SetBrush($parent->{transparent_brush});
-        $dc->DrawRectangle(0, 0, @size);
-    }
-    
-    # draw text if plate is empty
-    if (!@{$parent->{objects}}) {
-        $dc->SetTextForeground(Wx::Colour->new(150,50,50));
-        $dc->SetFont(Wx::Font->new(14, wxDEFAULT, wxNORMAL, wxNORMAL));
-        $dc->DrawLabel(CANVAS_TEXT, Wx::Rect->new(0, 0, $self->GetSize->GetWidth, $self->GetSize->GetHeight), wxALIGN_CENTER_HORIZONTAL | wxALIGN_CENTER_VERTICAL);
-    }
-    
-    # draw thumbnails
-    $dc->SetPen(wxBLACK_PEN);
-    $parent->clean_instance_thumbnails;
-    for my $obj_idx (0 .. $#{$parent->{objects}}) {
-        my $object = $parent->{objects}[$obj_idx];
-        my $model_object = $parent->{model}->objects->[$obj_idx];
-        next unless defined $object->thumbnail;
-        for my $instance_idx (0 .. $#{$model_object->instances}) {
-            my $instance = $model_object->instances->[$instance_idx];
-            next if !defined $object->transformed_thumbnail;
-            
-            my $thumbnail = $object->transformed_thumbnail->clone;      # in scaled model coordinates
-            $thumbnail->translate(map scale($_), @{$instance->offset});
-            
-            $object->instance_thumbnails->[$instance_idx] = $thumbnail;
-            
-            if (defined $self->{drag_object} && $self->{drag_object}[0] == $obj_idx && $self->{drag_object}[1] == $instance_idx) {
-                $dc->SetBrush($parent->{dragged_brush});
-            } elsif ($object->selected) {
-                $dc->SetBrush($parent->{selected_brush});
-            } else {
-                $dc->SetBrush($parent->{objects_brush});
-            }
-            foreach my $expolygon (@$thumbnail) {
-                foreach my $points (@{$expolygon->pp}) {
-                    $dc->DrawPolygon($parent->points_to_pixel($points, 1), 0, 0);
-                }
-            }
-            
-            if (0) {
-                # draw bounding box for debugging purposes
-                my $bb = $model_object->instance_bounding_box($instance_idx);
-                $bb->scale($parent->{scaling_factor});
-                # no need to translate by instance offset because instance_bounding_box() does that
-                my $points = $bb->polygon->pp;
-                $dc->SetPen($parent->{clearance_pen});
-                $dc->SetBrush($parent->{transparent_brush});
-                $dc->DrawPolygon($parent->_y($points), 0, 0);
-            }
-            
-            # if sequential printing is enabled and we have more than one object, draw clearance area
-            if ($parent->{config}->complete_objects && (map @{$_->instances}, @{$parent->{model}->objects}) > 1) {
-                my ($clearance) = @{offset([$thumbnail->convex_hull], (scale($parent->{config}->extruder_clearance_radius) / 2), 1, JT_ROUND, scale(0.1))};
-                $dc->SetPen($parent->{clearance_pen});
-                $dc->SetBrush($parent->{transparent_brush});
-                $dc->DrawPolygon($parent->points_to_pixel($clearance, 1), 0, 0);
-            }
-        }
-    }
-    
-    # draw skirt
-    if (@{$parent->{objects}} && $parent->{config}->skirts) {
-        my @points = map @{$_->contour}, map @$_, map @{$_->instance_thumbnails}, @{$parent->{objects}};
-        if (@points >= 3) {
-            my ($convex_hull) = @{offset([convex_hull(\@points)], scale($parent->{config}->skirt_distance), 1, JT_ROUND, scale(0.1))};
-            $dc->SetPen($parent->{skirt_pen});
-            $dc->SetBrush($parent->{transparent_brush});
-            $dc->DrawPolygon($parent->points_to_pixel($convex_hull, 1), 0, 0);
-        }
-    }
-    
-    $event->Skip;
-}
-
-sub mouse_event {
-    my ($self, $event) = @_;
-    my $parent = $self->GetParent;
-    
-    my $point = $event->GetPosition;
-    my $pos = $parent->point_to_model_units([ $point->x, $point->y ]);  #]]
-    $pos = Slic3r::Point->new_scale(@$pos);
-    if ($event->ButtonDown(&Wx::wxMOUSE_BTN_LEFT)) {
-        $parent->select_object(undef);
-        for my $obj_idx (0 .. $#{$parent->{objects}}) {
-            my $object = $parent->{objects}->[$obj_idx];
-            for my $instance_idx (0 .. $#{ $object->instance_thumbnails }) {
-                my $thumbnail = $object->instance_thumbnails->[$instance_idx];
-                if (defined first { $_->contour->contains_point($pos) } @$thumbnail) {
-                    $parent->select_object($obj_idx);
-                    my $instance = $parent->{model}->objects->[$obj_idx]->instances->[$instance_idx];
-                    my $instance_origin = [ map scale($_), @{$instance->offset} ];
-                    $self->{drag_start_pos} = [   # displacement between the click and the instance origin in scaled model units
-                        $pos->x - $instance_origin->[X],
-                        $pos->y - $instance_origin->[Y],  #-
-                    ];
-                    $self->{drag_object} = [ $obj_idx, $instance_idx ];
-                }
-            }
-        }
-        $parent->Refresh;
-    } elsif ($event->ButtonUp(&Wx::wxMOUSE_BTN_LEFT)) {
-        $parent->update;
-        $parent->Refresh;
-        $self->{drag_start_pos} = undef;
-        $self->{drag_object} = undef;
-        $self->SetCursor(wxSTANDARD_CURSOR);
-    } elsif ($event->ButtonDClick) {
-    	$parent->object_cut_dialog if $parent->selected_object;
-    } elsif ($event->Dragging) {
-        return if !$self->{drag_start_pos}; # concurrency problems
-        my ($obj_idx, $instance_idx) = @{ $self->{drag_object} };
-        my $model_object = $parent->{model}->objects->[$obj_idx];
-        $model_object->instances->[$instance_idx]->set_offset(
-            Slic3r::Pointf->new(
-                unscale($pos->[X] - $self->{drag_start_pos}[X]),
-                unscale($pos->[Y] - $self->{drag_start_pos}[Y]),
-            ));
-        $model_object->update_bounding_box;
-        $parent->Refresh;
-    } elsif ($event->Moving) {
-        my $cursor = wxSTANDARD_CURSOR;
-        if (defined first { $_->contour->contains_point($pos) } map @$_, map @{$_->instance_thumbnails}, @{ $parent->{objects} }) {
-            $cursor = Wx::Cursor->new(wxCURSOR_HAND);
-        }
-        $self->SetCursor($cursor);
-    }
-}
-
 sub list_item_deselected {
     my ($self, $event) = @_;
     return if $PreventListEvents;
@@ -1314,50 +1130,6 @@ sub statusbar {
     return $self->skeinpanel->GetParent->{statusbar};
 }
 
-# coordinates of the model origin (0,0) in pixels
-sub model_origin_to_pixel {
-    my ($self) = @_;
-    
-    return [
-        CANVAS_SIZE->[X]/2 - ($self->{config}->print_center->[X] * $self->{scaling_factor}),
-        CANVAS_SIZE->[Y]/2 - ($self->{config}->print_center->[Y] * $self->{scaling_factor}),
-    ];
-}
-
-# convert a model coordinate into a pixel coordinate, assuming preview has square shape
-sub point_to_pixel {
-    my ($self, $point) = @_;
-    
-    my $canvas_height = $self->{canvas}->GetSize->GetHeight;
-    my $zero = $self->model_origin_to_pixel;
-    return [
-                          $point->[X] * $self->{scaling_factor} + $zero->[X],
-        $canvas_height - ($point->[Y] * $self->{scaling_factor} + $zero->[Y]),
-    ];
-}
-
-sub points_to_pixel {
-    my ($self, $points, $unscale) = @_;
-    
-    my $result = [];
-    foreach my $point (@$points) {
-        $point = [ map unscale($_), @$point ] if $unscale;
-        push @$result, $self->point_to_pixel($point);
-    }
-    return $result;
-}
-
-sub point_to_model_units {
-    my ($self, $point) = @_;
-    
-    my $canvas_height = $self->{canvas}->GetSize->GetHeight;
-    my $zero = $self->model_origin_to_pixel;
-    return [
-                          ($point->[X] - $zero->[X]) / $self->{scaling_factor},
-        (($canvas_height - $point->[Y] - $zero->[Y]) / $self->{scaling_factor}),
-    ];
-}
-
 package Slic3r::GUI::Plater::DropTarget;
 use Wx::DND;
 use base 'Wx::FileDropTarget';
diff --git a/lib/Slic3r/GUI/Plater/2D.pm b/lib/Slic3r/GUI/Plater/2D.pm
new file mode 100644
index 00000000..08765772
--- /dev/null
+++ b/lib/Slic3r/GUI/Plater/2D.pm
@@ -0,0 +1,284 @@
+package Slic3r::GUI::Plater::2D;
+use strict;
+use warnings;
+use utf8;
+
+use List::Util qw(max first);
+use Slic3r::Geometry qw(X Y scale unscale convex_hull);
+use Slic3r::Geometry::Clipper qw(offset JT_ROUND);
+use Wx qw(:misc :pen :brush :sizer :font :cursor wxTAB_TRAVERSAL);
+use Wx::Event qw(EVT_MOUSE_EVENTS EVT_PAINT);
+use base 'Wx::Panel';
+
+use constant CANVAS_TEXT => join('-', +(localtime)[3,4]) eq '13-8'
+    ? 'What do you want to print today? ™' # Sept. 13, 2006. The first part ever printed by a RepRap to make another RepRap.
+    : 'Drag your objects here';
+
+sub new {
+    my $class = shift;
+    my ($parent, $size, $objects, $model, $config) = @_;
+    
+    my $self = $class->SUPER::new($parent, -1, wxDefaultPosition, $size, wxTAB_TRAVERSAL);
+    $self->SetBackgroundColour(Wx::wxWHITE);
+    
+    $self->{objects}            = $objects;
+    $self->{model}              = $model;
+    $self->{config}             = $config;
+    $self->{on_select_object}   = sub {};
+    $self->{on_double_click}    = sub {};
+    $self->{on_instance_moved}  = sub {};
+    
+    $self->{objects_brush}      = Wx::Brush->new(Wx::Colour->new(210,210,210), wxSOLID);
+    $self->{selected_brush}     = Wx::Brush->new(Wx::Colour->new(255,128,128), wxSOLID);
+    $self->{dragged_brush}      = Wx::Brush->new(Wx::Colour->new(128,128,255), wxSOLID);
+    $self->{transparent_brush}  = Wx::Brush->new(Wx::Colour->new(0,0,0), wxTRANSPARENT);
+    $self->{grid_pen}           = Wx::Pen->new(Wx::Colour->new(230,230,230), 1, wxSOLID);
+    $self->{print_center_pen}   = Wx::Pen->new(Wx::Colour->new(200,200,200), 1, wxSOLID);
+    $self->{clearance_pen}      = Wx::Pen->new(Wx::Colour->new(0,0,200), 1, wxSOLID);
+    $self->{skirt_pen}          = Wx::Pen->new(Wx::Colour->new(150,150,150), 1, wxSOLID);
+    
+    EVT_PAINT($self, \&repaint);
+    EVT_MOUSE_EVENTS($self, \&mouse_event);
+    
+    return $self;
+}
+
+sub on_select_object {
+    my ($self, $cb) = @_;
+    $self->{on_select_object} = $cb;
+}
+
+sub on_double_click {
+    my ($self, $cb) = @_;
+    $self->{on_double_click} = $cb;
+}
+
+sub on_instance_moved {
+    my ($self, $cb) = @_;
+    $self->{on_instance_moved} = $cb;
+}
+
+sub repaint {
+    my ($self, $event) = @_;
+    
+    my $dc = Wx::PaintDC->new($self);
+    my $size = $self->GetSize;
+    my @size = ($size->GetWidth, $size->GetHeight);
+    
+    # draw grid
+    $dc->SetPen($self->{grid_pen});
+    my $step = 10 * $self->{scaling_factor};
+    for (my $x = $step; $x <= $size[X]; $x += $step) {
+        $dc->DrawLine($x, 0, $x, $size[Y]);
+    }
+    for (my $y = $step; $y <= $size[Y]; $y += $step) {
+        $dc->DrawLine(0, $y, $size[X], $y);
+    }
+    
+    # draw print center
+    if (@{$self->{objects}}) {
+        $dc->SetPen($self->{print_center_pen});
+        $dc->DrawLine($size[X]/2, 0, $size[X]/2, $size[Y]);
+        $dc->DrawLine(0, $size[Y]/2, $size[X], $size[Y]/2);
+        $dc->SetTextForeground(Wx::Colour->new(0,0,0));
+        $dc->SetFont(Wx::Font->new(10, wxDEFAULT, wxNORMAL, wxNORMAL));
+        $dc->DrawLabel("X = " . $self->{config}->print_center->[X], Wx::Rect->new(0, 0, $self->GetSize->GetWidth, $self->GetSize->GetHeight), wxALIGN_CENTER_HORIZONTAL | wxALIGN_BOTTOM);
+        $dc->DrawRotatedText("Y = " . $self->{config}->print_center->[Y], 0, $size[Y]/2+15, 90);
+    }
+    
+    # draw frame
+    if (0) {
+        $dc->SetPen(wxBLACK_PEN);
+        $dc->SetBrush($self->{transparent_brush});
+        $dc->DrawRectangle(0, 0, @size);
+    }
+    
+    # draw text if plate is empty
+    if (!@{$self->{objects}}) {
+        $dc->SetTextForeground(Wx::Colour->new(150,50,50));
+        $dc->SetFont(Wx::Font->new(14, wxDEFAULT, wxNORMAL, wxNORMAL));
+        $dc->DrawLabel(CANVAS_TEXT, Wx::Rect->new(0, 0, $self->GetSize->GetWidth, $self->GetSize->GetHeight), wxALIGN_CENTER_HORIZONTAL | wxALIGN_CENTER_VERTICAL);
+    }
+    
+    # draw thumbnails
+    $dc->SetPen(wxBLACK_PEN);
+    $self->clean_instance_thumbnails;
+    for my $obj_idx (0 .. $#{$self->{objects}}) {
+        my $object = $self->{objects}[$obj_idx];
+        my $model_object = $self->{model}->objects->[$obj_idx];
+        next unless defined $object->thumbnail;
+        for my $instance_idx (0 .. $#{$model_object->instances}) {
+            my $instance = $model_object->instances->[$instance_idx];
+            next if !defined $object->transformed_thumbnail;
+            
+            my $thumbnail = $object->transformed_thumbnail->clone;      # in scaled model coordinates
+            $thumbnail->translate(map scale($_), @{$instance->offset});
+            
+            $object->instance_thumbnails->[$instance_idx] = $thumbnail;
+            
+            if (defined $self->{drag_object} && $self->{drag_object}[0] == $obj_idx && $self->{drag_object}[1] == $instance_idx) {
+                $dc->SetBrush($self->{dragged_brush});
+            } elsif ($object->selected) {
+                $dc->SetBrush($self->{selected_brush});
+            } else {
+                $dc->SetBrush($self->{objects_brush});
+            }
+            foreach my $expolygon (@$thumbnail) {
+                foreach my $points (@{$expolygon->pp}) {
+                    $dc->DrawPolygon($self->points_to_pixel($points, 1), 0, 0);
+                }
+            }
+            
+            if (0) {
+                # draw bounding box for debugging purposes
+                my $bb = $model_object->instance_bounding_box($instance_idx);
+                $bb->scale($self->{scaling_factor});
+                # no need to translate by instance offset because instance_bounding_box() does that
+                my $points = $bb->polygon->pp;
+                $dc->SetPen($self->{clearance_pen});
+                $dc->SetBrush($self->{transparent_brush});
+                $dc->DrawPolygon($self->_y($points), 0, 0);
+            }
+            
+            # if sequential printing is enabled and we have more than one object, draw clearance area
+            if ($self->{config}->complete_objects && (map @{$_->instances}, @{$self->{model}->objects}) > 1) {
+                my ($clearance) = @{offset([$thumbnail->convex_hull], (scale($self->{config}->extruder_clearance_radius) / 2), 1, JT_ROUND, scale(0.1))};
+                $dc->SetPen($self->{clearance_pen});
+                $dc->SetBrush($self->{transparent_brush});
+                $dc->DrawPolygon($self->points_to_pixel($clearance, 1), 0, 0);
+            }
+        }
+    }
+    
+    # draw skirt
+    if (@{$self->{objects}} && $self->{config}->skirts) {
+        my @points = map @{$_->contour}, map @$_, map @{$_->instance_thumbnails}, @{$self->{objects}};
+        if (@points >= 3) {
+            my ($convex_hull) = @{offset([convex_hull(\@points)], scale($self->{config}->skirt_distance), 1, JT_ROUND, scale(0.1))};
+            $dc->SetPen($self->{skirt_pen});
+            $dc->SetBrush($self->{transparent_brush});
+            $dc->DrawPolygon($self->points_to_pixel($convex_hull, 1), 0, 0);
+        }
+    }
+    
+    $event->Skip;
+}
+
+sub mouse_event {
+    my ($self, $event) = @_;
+    
+    my $point = $event->GetPosition;
+    my $pos = $self->point_to_model_units([ $point->x, $point->y ]);  #]]
+    $pos = Slic3r::Point->new_scale(@$pos);
+    if ($event->ButtonDown(&Wx::wxMOUSE_BTN_LEFT)) {
+        $self->{on_select_object}->(undef);
+        for my $obj_idx (0 .. $#{$self->{objects}}) {
+            my $object = $self->{objects}->[$obj_idx];
+            for my $instance_idx (0 .. $#{ $object->instance_thumbnails }) {
+                my $thumbnail = $object->instance_thumbnails->[$instance_idx];
+                if (defined first { $_->contour->contains_point($pos) } @$thumbnail) {
+                    $self->{on_select_object}->($obj_idx);
+                    my $instance = $self->{model}->objects->[$obj_idx]->instances->[$instance_idx];
+                    my $instance_origin = [ map scale($_), @{$instance->offset} ];
+                    $self->{drag_start_pos} = [   # displacement between the click and the instance origin in scaled model units
+                        $pos->x - $instance_origin->[X],
+                        $pos->y - $instance_origin->[Y],  #-
+                    ];
+                    $self->{drag_object} = [ $obj_idx, $instance_idx ];
+                }
+            }
+        }
+        $self->Refresh;
+    } elsif ($event->ButtonUp(&Wx::wxMOUSE_BTN_LEFT)) {
+        $self->{on_instance_moved}->();
+        $self->Refresh;
+        $self->{drag_start_pos} = undef;
+        $self->{drag_object} = undef;
+        $self->SetCursor(wxSTANDARD_CURSOR);
+    } elsif ($event->ButtonDClick) {
+    	$self->{on_double_click}->();
+    } elsif ($event->Dragging) {
+        return if !$self->{drag_start_pos}; # concurrency problems
+        my ($obj_idx, $instance_idx) = @{ $self->{drag_object} };
+        my $model_object = $self->{model}->objects->[$obj_idx];
+        $model_object->instances->[$instance_idx]->set_offset(
+            Slic3r::Pointf->new(
+                unscale($pos->[X] - $self->{drag_start_pos}[X]),
+                unscale($pos->[Y] - $self->{drag_start_pos}[Y]),
+            ));
+        $model_object->update_bounding_box;
+        $self->Refresh;
+    } elsif ($event->Moving) {
+        my $cursor = wxSTANDARD_CURSOR;
+        if (defined first { $_->contour->contains_point($pos) } map @$_, map @{$_->instance_thumbnails}, @{ $self->{objects} }) {
+            $cursor = Wx::Cursor->new(wxCURSOR_HAND);
+        }
+        $self->SetCursor($cursor);
+    }
+}
+
+sub update_bed_size {
+    my $self = shift;
+    
+    # supposing the preview canvas is square, calculate the scaling factor
+    # to constrain print bed area inside preview
+    # when the canvas is not rendered yet, its GetSize() method returns 0,0
+    # scaling_factor is expressed in pixel / mm
+    my $width = $self->GetSize->GetWidth;
+    $self->{scaling_factor} = $width / max(@{ $self->{config}->bed_size })
+        if $width != 0;
+}
+
+sub clean_instance_thumbnails {
+    my ($self) = @_;
+    
+    foreach my $object (@{ $self->{objects} }) {
+        @{ $object->instance_thumbnails } = ();
+    }
+}
+
+# coordinates of the model origin (0,0) in pixels
+sub model_origin_to_pixel {
+    my ($self) = @_;
+    
+    return [
+        $self->GetSize->GetWidth/2 - ($self->{config}->print_center->[X] * $self->{scaling_factor}),
+        $self->GetSize->GetHeight/2 - ($self->{config}->print_center->[Y] * $self->{scaling_factor}),
+    ];
+}
+
+# convert a model coordinate into a pixel coordinate, assuming preview has square shape
+sub point_to_pixel {
+    my ($self, $point) = @_;
+    
+    my $canvas_height = $self->GetSize->GetHeight;
+    my $zero = $self->model_origin_to_pixel;
+    return [
+                          $point->[X] * $self->{scaling_factor} + $zero->[X],
+        $canvas_height - ($point->[Y] * $self->{scaling_factor} + $zero->[Y]),
+    ];
+}
+
+sub points_to_pixel {
+    my ($self, $points, $unscale) = @_;
+    
+    my $result = [];
+    foreach my $point (@$points) {
+        $point = [ map unscale($_), @$point ] if $unscale;
+        push @$result, $self->point_to_pixel($point);
+    }
+    return $result;
+}
+
+sub point_to_model_units {
+    my ($self, $point) = @_;
+    
+    my $canvas_height = $self->GetSize->GetHeight;
+    my $zero = $self->model_origin_to_pixel;
+    return [
+                          ($point->[X] - $zero->[X]) / $self->{scaling_factor},
+        (($canvas_height - $point->[Y] - $zero->[Y]) / $self->{scaling_factor}),
+    ];
+}
+
+1;