From 9713b9f524da2fc7c8cd63f9013f311633cb047a Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Wed, 13 Mar 2013 14:55:58 +0100
Subject: [PATCH] Fix narrow fills growing

---
 lib/Slic3r/Fill.pm             | 14 ++++++++++----
 lib/Slic3r/Geometry/Clipper.pm | 10 +++++++++-
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/lib/Slic3r/Fill.pm b/lib/Slic3r/Fill.pm
index 1a76c6a670..f954c0599f 100644
--- a/lib/Slic3r/Fill.pm
+++ b/lib/Slic3r/Fill.pm
@@ -13,7 +13,7 @@ use Slic3r::Fill::PlanePath;
 use Slic3r::Fill::Rectilinear;
 use Slic3r::ExtrusionPath ':roles';
 use Slic3r::Geometry qw(X Y PI scale chained_path);
-use Slic3r::Geometry::Clipper qw(union_ex diff_ex intersection_ex offset);
+use Slic3r::Geometry::Clipper qw(union_ex diff diff_ex intersection_ex offset);
 use Slic3r::Surface ':types';
 
 
@@ -109,19 +109,25 @@ sub make_fill {
     # any void neighbors
     my $distance_between_surfaces = $layerm->infill_flow->scaled_spacing;
     {
-        my $collapsed = diff_ex(
+        my $collapsed = diff(
             [ map @{$_->expolygon}, @surfaces ],
             [ offset(
                 [ offset([ map @{$_->expolygon}, @surfaces ], -$distance_between_surfaces/2) ],
                 +$distance_between_surfaces/2
             ) ],
+            1,
         );
         push @surfaces, map Slic3r::Surface->new(
             expolygon       => $_,
             surface_type    => S_TYPE_INTERNALSOLID,
         ), @{intersection_ex(
-            [ offset([ map @$_, @$collapsed ], $distance_between_surfaces) ],
-            [ map @{$_->expolygon}, grep $_->surface_type == S_TYPE_INTERNALVOID, @surfaces ],
+            [ offset($collapsed, $distance_between_surfaces) ],
+            [
+                (map @{$_->expolygon}, grep $_->surface_type == S_TYPE_INTERNALVOID, @surfaces),
+                (@$collapsed),
+            ],
+            undef,
+            1,
         )};
     }
     
diff --git a/lib/Slic3r/Geometry/Clipper.pm b/lib/Slic3r/Geometry/Clipper.pm
index 292e88f27f..724f6994ea 100644
--- a/lib/Slic3r/Geometry/Clipper.pm
+++ b/lib/Slic3r/Geometry/Clipper.pm
@@ -45,7 +45,15 @@ sub diff_ex {
 }
 
 sub diff {
-    return [ map @$_, diff_ex(@_) ];
+    my ($subject, $clip, $safety_offset) = @_;
+    
+    $clipper->clear;
+    $clipper->add_subject_polygons($subject);
+    $clipper->add_clip_polygons($safety_offset ? safety_offset($clip) : $clip);
+    return [
+        map Slic3r::Polygon->new($_),
+            @{ $clipper->execute(CT_DIFFERENCE, PFT_NONZERO, PFT_NONZERO) },
+    ];
 }
 
 sub union_ex {