From 494ed5c5adb9b9afae9b9af992e9cc1fab4232f8 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Mon, 26 Aug 2013 22:54:06 +0200
Subject: [PATCH] Minor optimization (group offset_ex calls)

---
 lib/Slic3r/Print/Object.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index f64965cb..fe44179f 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -594,7 +594,7 @@ sub discover_horizontal_shells {
                 # not work in some situations, as there won't be any grown region in the perimeter 
                 # area (this was seen in a model where the top layer had one extra perimeter, thus
                 # its fill_surfaces was thinner than the lower layer's infill)
-                my $solid = [ map $_->expolygon->offset_ex($margin), grep $_->surface_type == $type, @{$layerm->slices} ];
+                my $solid = offset_ex([ map $_->p, grep $_->surface_type == $type, @{$layerm->slices} ], $margin);
                 next if !@$solid;
                 Slic3r::debugf "Layer %d has %s surfaces\n", $i, ($type == S_TYPE_TOP) ? 'top' : 'bottom';