From a88ce0cb5eb444ac9988dd36798b024cc00b9a8a Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Mon, 16 Sep 2013 18:42:28 +0200
Subject: [PATCH] Fix regression in start perimeters at non-overhangs. #1442

---
 lib/Slic3r/ExtrusionPath.pm |  8 ++++----
 lib/Slic3r/GCode.pm         | 18 +++++++++---------
 lib/Slic3r/Polygon.pm       |  7 ++++---
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/lib/Slic3r/ExtrusionPath.pm b/lib/Slic3r/ExtrusionPath.pm
index 85ab900ed..be97e3baa 100644
--- a/lib/Slic3r/ExtrusionPath.pm
+++ b/lib/Slic3r/ExtrusionPath.pm
@@ -29,18 +29,18 @@ sub clip_with_expolygon {
 
 sub intersect_expolygons {
     my $self = shift;
-    my ($expolygons) = @_;
+    my ($expolygons_pp) = @_;
     
     return map $self->clone(polyline => Slic3r::Polyline->new(@$_)),
-        @{Boost::Geometry::Utils::multi_polygon_multi_linestring_intersection([ map $_->pp, @$expolygons ], [$self->pp])};
+        @{Boost::Geometry::Utils::multi_polygon_multi_linestring_intersection($expolygons_pp, [$self->pp])};
 }
 
 sub subtract_expolygons {
     my $self = shift;
-    my ($expolygons) = @_;
+    my ($expolygons_pp) = @_;
     
     return map $self->clone(polyline => Slic3r::Polyline->new(@$_)),
-        @{Boost::Geometry::Utils::multi_linestring_multi_polygon_difference([$self->pp], [ map $_->pp, @$expolygons ])};
+        @{Boost::Geometry::Utils::multi_linestring_multi_polygon_difference([$self->pp], $expolygons_pp)};
 }
 
 sub simplify {
diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index 53d6eabe0..c0abf1bc6 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -16,7 +16,7 @@ has 'layer_count'        => (is => 'ro', required => 1 );
 has 'layer'              => (is => 'rw');
 has '_layer_islands'     => (is => 'rw');
 has '_upper_layer_islands'  => (is => 'rw');
-has '_layer_overhangs'   => (is => 'rw');
+has '_layer_overhangs_pp' => (is => 'rw');
 has 'shift_x'            => (is => 'rw', default => sub {0} );
 has 'shift_y'            => (is => 'rw', default => sub {0} );
 has 'z'                  => (is => 'rw');
@@ -99,10 +99,10 @@ sub change_layer {
         $self->_layer_islands([]);
         $self->_upper_layer_islands([]);
     }
-    $self->_layer_overhangs(
+    $self->_layer_overhangs_pp(
         # clone ExPolygons because they come from Surface objects but will be used outside here
-        $layer->id > 0 && ($layer->config->overhangs || $Slic3r::Config->start_perimeters_at_non_overhang)
-            ? [ map $_->expolygon->clone, grep $_->surface_type == S_TYPE_BOTTOM, map @{$_->slices}, @{$layer->regions} ]
+        ($layer->id > 0 && ($layer->config->overhangs || $Slic3r::Config->start_perimeters_at_non_overhang))
+            ? [ map $_->expolygon->pp, grep $_->surface_type == S_TYPE_BOTTOM, map @{$_->slices}, @{$layer->regions} ]
             : []
         );
     if ($self->config->avoid_crossing_perimeters) {
@@ -180,7 +180,7 @@ sub extrude_loop {
     }
     my @candidates = ();
     if ($Slic3r::Config->start_perimeters_at_non_overhang) {
-        @candidates = grep !Boost::Geometry::Utils::point_covered_by_multi_polygon($_->pp, $self->_layer_overhangs), @concave;
+        @candidates = grep !Boost::Geometry::Utils::point_covered_by_multi_polygon($_->pp, $self->_layer_overhangs_pp), @concave;
     }
     if (!@candidates) {
         # if none, look for any concave vertex
@@ -188,7 +188,7 @@ sub extrude_loop {
         if (!@candidates) {
             # if none, look for any non-overhang vertex
             if ($Slic3r::Config->start_perimeters_at_non_overhang) {
-                @candidates = grep !Boost::Geometry::Utils::point_covered_by_multi_polygon($_->pp, $self->_layer_overhangs), @{$polygon};
+                @candidates = grep !Boost::Geometry::Utils::point_covered_by_multi_polygon($_->pp, $self->_layer_overhangs_pp), @$polygon;
             }
             if (!@candidates) {
                 # if none, all points are valid candidates
@@ -218,15 +218,15 @@ sub extrude_loop {
     
     my @paths = ();
     # detect overhanging/bridging perimeters
-    if ($self->layer->config->overhangs && $extrusion_path->is_perimeter && @{$self->_layer_overhangs}) {
+    if ($self->layer->config->overhangs && $extrusion_path->is_perimeter && @{$self->_layer_overhangs_pp}) {
         # get non-overhang paths by subtracting overhangs from the loop
         push @paths,
-            $extrusion_path->subtract_expolygons($self->_layer_overhangs);
+            $extrusion_path->subtract_expolygons($self->_layer_overhangs_pp);
         
         # get overhang paths by intersecting overhangs with the loop
         push @paths,
             map { $_->role(EXTR_ROLE_OVERHANG_PERIMETER); $_ }
-            $extrusion_path->intersect_expolygons($self->_layer_overhangs);
+            $extrusion_path->intersect_expolygons($self->_layer_overhangs_pp);
         
         # reapply the nearest point search for starting point
         # (clone because the collection gets DESTROY'ed)
diff --git a/lib/Slic3r/Polygon.pm b/lib/Slic3r/Polygon.pm
index 5f6dc892a..963c13fa2 100644
--- a/lib/Slic3r/Polygon.pm
+++ b/lib/Slic3r/Polygon.pm
@@ -69,9 +69,10 @@ sub subdivide {
 sub concave_points {
     my $self = shift;
     
-    my @points = @{$self->pp};
-    return map $self->[$_],
-        grep Slic3r::Geometry::angle3points(@points[$_, $_-1, $_+1]) < PI - epsilon,
+    my @points = @$self;
+    my @points_pp = @{$self->pp};
+    return map $points[$_],
+        grep Slic3r::Geometry::angle3points(@points_pp[$_, $_-1, $_+1]) < PI - epsilon,
         -1 .. ($#points-1);
 }