From b495e15d7f17604c62cee5083153e3aa1cb892e4 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Thu, 29 Nov 2012 19:13:52 +0100
Subject: [PATCH] Fix plater slowness after the introduction of the vertical
 projection

---
 lib/Slic3r/GUI/Plater.pm   | 13 +++++++------
 lib/Slic3r/TriangleMesh.pm |  5 +++--
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index 724a5259..a8b30cba 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -1119,20 +1119,21 @@ sub make_thumbnail {
     my @points = map [ @$_[X,Y] ], @{$self->model_object->mesh->vertices};
     my $mesh = $self->model_object->mesh;
     my $thumbnail = Slic3r::ExPolygon::Collection->new(
-    	expolygons => (@{$mesh->facets} <= 2000)
+    	expolygons => (@{$mesh->facets} <= 5000)
     		? $mesh->horizontal_projection
     		: [ Slic3r::ExPolygon->new(convex_hull($mesh->vertices)) ],
     );
     for (map @$_, map @$_, @{$thumbnail->expolygons}) {
         @$_ = map $_ * $self->thumbnail_scaling_factor, @$_;
     }
-    for (@{$thumbnail->expolygons}) {
-	    $_->simplify(0.3);
-    	$_->rotate(Slic3r::Geometry::deg2rad($self->rotate));
-    	$_->scale($self->scale);
+    foreach my $expolygon (@{$thumbnail->expolygons}) {
+    	@$expolygon = grep $_->area >= 1, @$expolygon;
+	    $expolygon->simplify(0.5);
+    	$expolygon->rotate(Slic3r::Geometry::deg2rad($self->rotate));
+    	$expolygon->scale($self->scale);
     }
+    @{$thumbnail->expolygons} = grep @$_, @{$thumbnail->expolygons};
     $thumbnail->align_to_origin;
-    
     $self->thumbnail($thumbnail);  # ignored in multi-threaded environments
     $self->free_model_object;
     
diff --git a/lib/Slic3r/TriangleMesh.pm b/lib/Slic3r/TriangleMesh.pm
index ea1204fe..59944596 100644
--- a/lib/Slic3r/TriangleMesh.pm
+++ b/lib/Slic3r/TriangleMesh.pm
@@ -584,11 +584,12 @@ sub horizontal_projection {
     
     my @f = ();
     foreach my $facet (@{$self->facets}) {
-        push @f, [ map [ @{$self->vertices->[$_]}[X,Y] ], @$facet ];
+        push @f, Slic3r::Polygon->new([ map [ @{$self->vertices->[$_]}[X,Y] ], @$facet ]);
     }
     
+    $_->make_counter_clockwise for @f;
     my $scale_vector = Math::Clipper::integerize_coordinate_sets({ bits => 32 }, @f);
-    my $union = union_ex([ Slic3r::Geometry::Clipper::offset(\@f, 1) ]);
+    my $union = union_ex([ Slic3r::Geometry::Clipper::offset(\@f, 10000) ]);
     Math::Clipper::unscale_coordinate_sets($scale_vector, $_) for @$union;
     return $union;
 }