New --no-extrusion option to disable E values

lib/Slic3r.pm

@@ -35,6 +35,7 @@ use Slic3r::Surface::Bridge;
 our $nozzle_diameter    = 0.5;
 our $print_center       = [100,100];  # object will be centered around this point
 our $use_relative_e_distances = 0;
+our $no_extrusion       = 0;
 our $z_offset           = 0;
 our $gcode_arcs         = 0;
 

lib/Slic3r/Config.pm

@@ -22,6 +22,10 @@ our $Options = {
         label   => 'Use relative E distances',
         type    => 'bool',
     },
+    'no_extrusion' => {
+        label   => 'No extrusion',
+        type    => 'bool',
+    },
     'z_offset' => {
         label   => 'Z offset',
         type    => 'f',

lib/Slic3r/Extruder.pm

@@ -222,7 +222,7 @@ sub _Gx {
     }
     
     # output extrusion distance
-    if ($e) {
+    if ($e && !$Slic3r::no_extrusion) {
         $self->extrusion_distance(0) if $Slic3r::use_relative_e_distances;
         $self->extrusion_distance($self->extrusion_distance + $e);
         $gcode .= sprintf " E%.5f", $self->extrusion_distance;

lib/Slic3r/GUI/SkeinPanel.pm

@@ -17,7 +17,7 @@ sub new {
     my %panels = (
         printer => Slic3r::GUI::OptionsGroup->new($self,
             title => 'Printer',
-            options => [qw(nozzle_diameter print_center use_relative_e_distances z_offset)],
+            options => [qw(nozzle_diameter print_center use_relative_e_distances no_extrusion z_offset)],
         ),
         filament => Slic3r::GUI::OptionsGroup->new($self,
             title => 'Filament',