From 5c9916dc75a0a59f5751de5672f49c8c95584e49 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Wed, 6 Jun 2012 22:28:23 +0200
Subject: [PATCH] Some basic ability to close holes in non-manifold models

---
 lib/Slic3r/TriangleMesh.pm | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/Slic3r/TriangleMesh.pm b/lib/Slic3r/TriangleMesh.pm
index f9b06c1b..4fa77ccd 100644
--- a/lib/Slic3r/TriangleMesh.pm
+++ b/lib/Slic3r/TriangleMesh.pm
@@ -237,7 +237,7 @@ sub make_loops {
         grep defined $lines[$_][I_A_ID],
         (0..$#lines);
     
-    my (@polygons, %visited_lines) = ();
+    my (@polygons, @failed_loops, %visited_lines) = ();
     CYCLE: for (my $i = 0; $i <= $#lines; $i++) {
         my $line = $lines[$i];
         next if $visited_lines{$line};
@@ -253,20 +253,24 @@ sub make_loops {
             } else {
                 Slic3r::debugf "  line has no next_facet_index or b_id\n";
                 $layer->slicing_errors(1);
+                push @failed_loops, [@points] if @points;
                 next CYCLE;
             }
             
             if (!$next_line || $visited_lines{$next_line}) {
                 Slic3r::debugf "  failed to close this loop\n";
                 $layer->slicing_errors(1);
+                push @failed_loops, [@points] if @points;
                 next CYCLE;
             } elsif (defined $next_line->[I_PREV_FACET_INDEX] && $next_line->[I_PREV_FACET_INDEX] != $line->[I_FACET_INDEX]) {
                 Slic3r::debugf "  wrong prev_facet_index\n";
                 $layer->slicing_errors(1);
+                push @failed_loops, [@points] if @points;
                 next CYCLE;
             } elsif (defined $next_line->[I_A_ID] && $next_line->[I_A_ID] != $line->[I_B_ID]) {
                 Slic3r::debugf "  wrong a_id\n";
                 $layer->slicing_errors(1);
+                push @failed_loops, [@points] if @points;
                 next CYCLE;
             }
             
@@ -281,6 +285,14 @@ sub make_loops {
             if $Slic3r::debug;
     }
     
+    # TODO: we should try to combine failed loops
+    for (grep @$_ >= 3, @failed_loops) {
+        push @polygons, Slic3r::Polygon->new(@$_);
+        Slic3r::debugf "  Discovered failed %s polygon of %d points\n",
+            ($polygons[-1]->is_counter_clockwise ? 'ccw' : 'cw'), scalar(@$_)
+            if $Slic3r::debug;
+    }
+    
     return [@polygons];
 }