From 075213c73115b53c3fffbed1f3fc0921e0c39da9 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Wed, 22 Aug 2012 18:57:03 +0200
Subject: [PATCH] Refactoring: make 'retracted' an attribute of the Extruder
 object

---
 lib/Slic3r/Extruder.pm |  1 +
 lib/Slic3r/GCode.pm    | 15 +++++++--------
 lib/Slic3r/Print.pm    |  4 ++++
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/lib/Slic3r/Extruder.pm b/lib/Slic3r/Extruder.pm
index 6425ab4e9..5ebaa9fc5 100644
--- a/lib/Slic3r/Extruder.pm
+++ b/lib/Slic3r/Extruder.pm
@@ -10,6 +10,7 @@ use constant OPTIONS => [qw(
 )];
 has $_ => (is => 'ro', required => 1) for @{&OPTIONS};
 
+has 'retracted'                 => (is => 'rw', default => sub {0} );
 has 'e_per_mm3'                 => (is => 'lazy');
 has 'retract_speed_mm_min'      => (is => 'lazy');
 has '_mm3_per_mm_cache'         => (is => 'ro', default => sub {{}});
diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index fe08723ef..a9f62fd5c 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -14,7 +14,6 @@ has 'extruder_idx'       => (is => 'rw', default => sub {0});
 has 'extrusion_distance' => (is => 'rw', default => sub {0} );
 has 'elapsed_time'       => (is => 'rw', default => sub {0} );  # seconds
 has 'total_extrusion_length' => (is => 'rw', default => sub {0} );
-has 'retracted'          => (is => 'rw', default => sub {1} );  # this spits out some plastic at start
 has 'lifted'             => (is => 'rw', default => sub {0} );
 has 'last_pos'           => (is => 'rw', default => sub { Slic3r::Point->new(0,0) } );
 has 'last_speed'         => (is => 'rw', default => sub {""});
@@ -150,7 +149,7 @@ sub extrude_path {
         if !points_coincide($self->last_pos, $path->points->[0]);
     
     # compensate retraction
-    $gcode .= $self->unretract if $self->retracted;
+    $gcode .= $self->unretract if $self->extruder->retracted;
     
     my $area;  # mm^3 of extrudate per mm of tool movement 
     if ($path->role == EXTR_ROLE_BRIDGE) {
@@ -198,7 +197,7 @@ sub retract {
     my %params = @_;
     
     return "" unless $self->extruder->retract_length > 0 
-        && !$self->retracted;
+        && !$self->extruder->retracted;
     
     # prepare moves
     $self->speed('retract');
@@ -232,7 +231,7 @@ sub retract {
             $gcode .= $self->G1(@$lift);
         }
     }
-    $self->retracted(1);
+    $self->extruder->retracted($self->extruder->retract_length + $self->extruder->retract_restart_extra);
     $self->lifted($self->extruder->retract_lift) if $lift;
     
     # reset extrusion distance during retracts
@@ -244,7 +243,7 @@ sub retract {
 
 sub unretract {
     my $self = shift;
-    $self->retracted(0);
+    
     my $gcode = "";
     
     if ($self->lifted) {
@@ -253,8 +252,8 @@ sub unretract {
     }
     
     $self->speed('retract');
-    $gcode .= $self->G0(undef, undef, ($self->extruder->retract_length + $self->extruder->retract_restart_extra), 
-        "compensate retraction");
+    $gcode .= $self->G0(undef, undef, $self->extruder->retracted, "compensate retraction");
+    $self->extruder->retracted(0);
     
     return $gcode;
 }
@@ -348,7 +347,7 @@ sub _Gx {
         my $speed_f = $speed eq 'retract'
             ? ($self->extruder->retract_speed_mm_min)
             : $self->speeds->{$speed};
-        if ($e && $self->layer->id == 0 && $comment !~ /retract/) {
+        if ($e && $self->layer && $self->layer->id == 0 && $comment !~ /retract/) {
             $speed_f = $Slic3r::Config->first_layer_speed =~ /^(\d+(?:\.\d+)?)%$/
                 ? ($speed_f * $1/100)
                 : $Slic3r::Config->first_layer_speed * 60;
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 314e08c12..16e0f03b0 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -569,6 +569,10 @@ sub write_gcode {
     print $fh $gcodegen->set_tool(0) if @$Slic3r::extruders > 1;
     print $fh $gcodegen->set_fan(0, 1) if $Slic3r::Config->cooling && $Slic3r::Config->disable_fan_first_layers;
     
+    # this spits out some platic at start from the first extruder
+    # (TODO: make this consistent in multi-head setups)
+    $gcodegen->retract;
+    
     # write start commands to file
     printf $fh $gcodegen->set_bed_temperature($Slic3r::Config->first_layer_bed_temperature, 1),
         if $Slic3r::Config->first_layer_bed_temperature && $Slic3r::Config->start_gcode !~ /M190/i;