From 662031bc2d6a49d1c3f09bb96e5e3512d51cddb7 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Mon, 13 Mar 2017 23:47:52 +0100
Subject: [PATCH] Print the brim using the support material extruder if we have
 a raft. #2957

---
 lib/Slic3r/Print/GCode.pm |  6 +++++-
 t/skirt_brim.t            | 35 ++++++++++++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/lib/Slic3r/Print/GCode.pm b/lib/Slic3r/Print/GCode.pm
index b851f5242..b2187f208 100644
--- a/lib/Slic3r/Print/GCode.pm
+++ b/lib/Slic3r/Print/GCode.pm
@@ -462,7 +462,11 @@ sub process_layer {
     
     # extrude brim
     if (!$self->_brim_done) {
-        $gcode .= $self->_gcodegen->set_extruder($self->print->regions->[0]->config->perimeter_extruder-1);
+        my $extr = $self->print->regions->[0]->config->perimeter_extruder-1;
+        if (my $o = first { $_->config->raft_layers > 0 } @{$self->objects}) {
+            $extr = $o->config->support_material_extruder-1;
+        }
+        $gcode .= $self->_gcodegen->set_extruder($extr);
         $self->_gcodegen->set_origin(Slic3r::Pointf->new(0,0));
         $self->_gcodegen->avoid_crossing_perimeters->set_use_external_mp(1);
         $gcode .= $self->_gcodegen->extrude($_, 'brim', $object->config->support_material_speed)
diff --git a/t/skirt_brim.t b/t/skirt_brim.t
index 9b2a0a126..d6181ba23 100644
--- a/t/skirt_brim.t
+++ b/t/skirt_brim.t
@@ -1,4 +1,4 @@
-use Test::More tests => 6;
+use Test::More tests => 8;
 use strict;
 use warnings;
 
@@ -89,6 +89,39 @@ use Slic3r::Test;
     ok Slic3r::Test::gcode($print), 'successful G-code generation when skirt_height = 0 and skirts > 0';
 }
 
+{
+    my $config = Slic3r::Config->new_from_defaults;
+    $config->set('skirts', 0);
+    $config->set('brim_width', 5);
+    $config->set('perimeter_extruder', 2);
+    $config->set('support_material_extruder', 3);
+    
+    my $test = sub {
+        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+        my $tool = undef;
+        my $brim_tool = undef;
+        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
+            my ($self, $cmd, $args, $info) = @_;
+        
+            if ($cmd =~ /^T(\d+)/) {
+                $tool = $1;
+            } elsif ($cmd eq 'G1' && $info->{extruding} && $info->{dist_XY} > 0) {
+                if (!defined $brim_tool) {
+                    # first extrusion is brim
+                    $brim_tool = $tool;
+                }
+            }
+        });
+        return $brim_tool;
+    };
+    is $test->(), $config->perimeter_extruder-1,
+        'brim is printed with the extruder used for the perimeters of first object';
+    
+    $config->set('raft_layers', 1);
+    is $test->(), $config->support_material_extruder-1,
+        'if raft is enabled, brim is printed with the extruder used for it';
+}
+
 {
     my $config = Slic3r::Config->new_from_defaults;
     $config->set('layer_height', 0.4);