New wipe feature

README.markdown

@@ -239,6 +239,7 @@ The author of the Silk icon set is Mark James.
         --retract-lift      Lift Z by the given distance in mm when retracting (default: 0)
         --retract-layer-change
                             Enforce a retraction before each Z move (default: yes)
+        --wipe              Wipe the nozzle while doing a retraction (default: no)
         
        Retraction options for multi-extruder setups:
         --retract-length-toolchange

lib/Slic3r/Config.pm

@@ -794,6 +794,15 @@ END
         deserialize => $deserialize_comma,
         default => [1],
     },
+    'wipe' => {
+        label   => 'Wipe before retract',
+        tooltip => 'This flag will move the nozzle while retracting to minimize the possible blob on leaky extruders.',
+        cli     => 'wipe!',
+        type    => 'bool',
+        serialize   => $serialize_comma,
+        deserialize => $deserialize_comma,
+        default => [0],
+    },
     'retract_length_toolchange' => {
         label   => 'Length',
         tooltip => 'When retraction is triggered before changing tool, filament is pulled back by the specified amount (the length is measured on raw filament, before it enters the extruder).',
@@ -1065,7 +1074,7 @@ sub new_from_cli {
     }
     
     $args{$_} = $Options->{$_}{deserialize}->($args{$_})
-        for grep exists $args{$_}, qw(print_center bed_size duplicate_grid extruder_offset retract_layer_change);
+        for grep exists $args{$_}, qw(print_center bed_size duplicate_grid extruder_offset retract_layer_change wipe);
     
     return $class->new(%args);
 }

lib/Slic3r/Extruder.pm

@@ -1,13 +1,13 @@
 package Slic3r::Extruder;
 use Moo;
 
-use Slic3r::Geometry qw(PI);
+use Slic3r::Geometry qw(PI scale);
 
 use constant OPTIONS => [qw(
     extruder_offset
     nozzle_diameter filament_diameter extrusion_multiplier temperature first_layer_temperature
     retract_length retract_lift retract_speed retract_restart_extra retract_before_travel
-    retract_layer_change retract_length_toolchange retract_restart_extra_toolchange
+    retract_layer_change retract_length_toolchange retract_restart_extra_toolchange wipe
 )];
 
 has 'id'    => (is => 'rw', required => 1);
@@ -18,6 +18,7 @@ has 'retracted'                 => (is => 'rw', default => sub {0} );
 has 'restart_extra'             => (is => 'rw', default => sub {0} );
 has 'e_per_mm3'                 => (is => 'lazy');
 has 'retract_speed_mm_min'      => (is => 'lazy');
+has 'scaled_wipe_distance'      => (is => 'lazy'); # scaled mm
 has '_mm3_per_mm_cache'         => (is => 'ro', default => sub {{}});
 
 sub _build_bridge_flow {
@@ -35,6 +36,11 @@ sub _build_retract_speed_mm_min {
     return $self->retract_speed * 60;
 }
 
+sub _build_scaled_wipe_distance {
+    my $self = shift;
+    return scale $self->retract_length / $self->retract_speed * $Slic3r::Config->travel_speed;
+}
+
 sub make_flow {
     my $self = shift;
     return Slic3r::Flow->new(nozzle_diameter => $self->nozzle_diameter, @_);

lib/Slic3r/GCode.pm

@@ -28,6 +28,7 @@ has 'last_pos'           => (is => 'rw', default => sub { Slic3r::Point->new(0,0
 has 'last_speed'         => (is => 'rw', default => sub {""});
 has 'last_f'             => (is => 'rw', default => sub {""});
 has 'last_fan_speed'     => (is => 'rw', default => sub {0});
+has 'wipe_path'          => (is => 'rw');
 has 'dec'                => (is => 'ro', default => sub { 3 } );
 
 # used for vibration limit:
@@ -150,6 +151,7 @@ sub extrude_loop {
     
     # extrude along the path
     my $gcode = $self->extrude_path($extrusion_path, $description);
+    $self->wipe_path($extrusion_path->polyline);
     
     # make a little move inwards before leaving loop
     if ($loop->role == EXTR_ROLE_EXTERNAL_PERIMETER) {
@@ -236,12 +238,15 @@ sub extrude_path {
         $path_length = unscale $path->length;
         $gcode .= $self->G2_G3($path->points->[-1], $path->orientation, 
             $path->center, $e * unscale $path_length, $description);
+        $self->wipe_path(undef);
     } else {
         foreach my $line ($path->lines) {
             my $line_length = unscale $line->length;
             $path_length += $line_length;
             $gcode .= $self->G1($line->[B], undef, $e * $line_length, $description);
         }
+        $self->wipe_path([ reverse @{$path->points}[0..$#{$path->points}] ])
+            if $Slic3r::Config->wipe;
     }
     
     if ($Slic3r::Config->cooling) {
@@ -347,6 +352,14 @@ sub retract {
     # if we already retracted, reduce the required amount of retraction
     $length -= $self->extruder->retracted;
     return "" unless $length > 0;
+    my $gcode = "";
+    
+    # wipe
+    my $wipe_path = ();
+    if ($Slic3r::Config->wipe && $self->wipe_path) {
+        $wipe_path = Slic3r::Polyline->new([ $self->last_pos, @{$self->wipe_path} ])
+            ->clip_start($self->extruder->scaled_wipe_distance);
+    }
     
     # prepare moves
     $self->speed('retract');
@@ -355,7 +368,6 @@ sub retract {
         ? undef
         : [undef, $self->z + $self->extruder->retract_lift, 0, 'lift plate during travel'];
     
-    my $gcode = "";
     if (($Slic3r::Config->g0 || $Slic3r::Config->gcode_flavor eq 'mach3') && $params{travel_to}) {
         if ($lift) {
             # combine lift and retract
@@ -370,8 +382,18 @@ sub retract {
         # combine Z change and retraction
         my $travel = [undef, $params{move_z}, $retract->[2], "change layer and $comment"];
         $gcode .= $self->G0(@$travel);
+    } else {
+        if ($wipe_path) {
+            $self->speed('travel');
+            # subdivide the retraction
+            my $total_wipe_length = $wipe_path->length;
+            for (1 .. $#$wipe_path) {
+                my $segment_length = $wipe_path->[$_-1]->distance_to($wipe_path->[$_]);
+                $gcode .= $self->G1($wipe_path->[$_], undef, $retract->[2] * ($segment_length / $total_wipe_length), $retract->[3] . ";_WIPE");
+            }
         } else {
             $gcode .= $self->G1(@$retract);
+        }
         if (!$self->lifted) {
             if (defined $params{move_z} && $self->extruder->retract_lift > 0) {
                 my $travel = [undef, $params{move_z} + $self->extruder->retract_lift, 0, 'move to next layer (' . $self->layer->id . ') and lift'];

lib/Slic3r/Polyline.pm

@@ -164,6 +164,7 @@ sub scale {
     return $self;
 }
 
+# removes the given distance from the end of the polyline
 sub clip_end {
     my $self = shift;
     my ($distance) = @_;
@@ -184,6 +185,30 @@ sub clip_end {
     }
 }
 
+# only keeps the given distance at the beginning of the polyline
+sub clip_start {
+    my $self = shift;
+    my ($distance) = @_;
+    
+    my $points = [];
+    
+    for (my $i = 1; $distance > 0 && $i <= $#$self; $i++) {
+        my $point = $self->[$i];
+        my $segment_length = $point->distance_to($self->[$i-1]);
+        if ($segment_length <= $distance) {
+            $distance -= $segment_length;
+            push @$points, $point;
+            next;
+        }
+        
+        my $new_point = Slic3r::Geometry::point_along_segment($self->[$i-1], $point, $distance);
+        push @$points, Slic3r::Point->new($new_point);
+        $distance = 0;
+    }
+    
+    return (ref $self)->new($points);
+}
+
 package Slic3r::Polyline::Collection;
 use Moo;
 

lib/Slic3r/Print.pm

@@ -957,7 +957,7 @@ sub write_gcode {
             Slic3r::debugf "  fan = %d%%, speed = %d%%\n", $fan_speed, $speed_factor * 100;
             
             if ($speed_factor < 1) {
-                $gcode =~ s/^(?=.*? [XY])(?=.*? E)(?<!;_BRIDGE_FAN_START\n)(G1 .*?F)(\d+(?:\.\d+)?)/
+                $gcode =~ s/^(?=.*? [XY])(?=.*? E)(?!;_WIPE)(?<!;_BRIDGE_FAN_START\n)(G1 .*?F)(\d+(?:\.\d+)?)/
                     my $new_speed = $2 * $speed_factor;
                     $1 . sprintf("%.${dec}f", $new_speed < $min_print_speed ? $min_print_speed : $new_speed)
                     /gexm;
@@ -973,6 +973,7 @@ sub write_gcode {
             $gcode =~ s/^;_BRIDGE_FAN_START\n/ $gcodegen->set_fan($Slic3r::Config->bridge_fan_speed, 1) /gmex;
             $gcode =~ s/^;_BRIDGE_FAN_END\n/ $gcodegen->set_fan($fan_speed, 1) /gmex;
         }
+        $gcode =~ s/;_WIPE//g;
         
         return $gcode;
     };

slic3r.pl

@@ -292,6 +292,7 @@ $j
     --retract-lift      Lift Z by the given distance in mm when retracting (default: $config->{retract_lift}[0])
     --retract-layer-change
                         Enforce a retraction before each Z move (default: yes)
+    --wipe              Wipe the nozzle while doing a retraction (default: no)
     
    Retraction options for multi-extruder setups:
     --retract-length-toolchange