From 0216448cfa77b72c3efa3313d6671bc9b083a3c6 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Fri, 25 Jan 2013 19:57:08 +0100
Subject: [PATCH] Read materials from OBJ files and store them in the
 TriangleMesh object. Now we need to use them...

---
 lib/Slic3r/Format/OBJ.pm   | 36 ++++++++++++++++++++++++++++++++----
 lib/Slic3r/Model.pm        |  6 ++++++
 lib/Slic3r/TriangleMesh.pm |  2 ++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/lib/Slic3r/Format/OBJ.pm b/lib/Slic3r/Format/OBJ.pm
index c5cc0855..bf065748 100644
--- a/lib/Slic3r/Format/OBJ.pm
+++ b/lib/Slic3r/Format/OBJ.pm
@@ -1,25 +1,53 @@
 package Slic3r::Format::OBJ;
 use Moo;
 
+use constant MERGE_DUPLICATE_VERTICES => 0;
+
 sub read_file {
     my $self = shift;
     my ($file) = @_;
     
     Slic3r::open(\my $fh, '<', $file) or die "Failed to open $file\n";
-    my $vertices = [];
-    my $facets = [];
+    my $vertices            = [];
+    my %unique_vertices     = ();  # cache for merging duplicate vertices
+    my %vertices_map        = ();  # cache for merging duplicate vertices (obj_v_id => v_id)
+    my $facets              = [];
+    my $facets_materials    = [];
+    my %materials           = (); # material_id => material_idx
+    my $cur_material_idx    = undef;
     while (my $_ = <$fh>) {
+        chomp;
         if (/^v ([^ ]+)\s+([^ ]+)\s+([^ ]+)/) {
             push @$vertices, [$1, $2, $3];
+            if (MERGE_DUPLICATE_VERTICES) {
+                my $key = "$1-$2-$3";
+                if (!exists $unique_vertices{$key}) {
+                    $unique_vertices{$key} = (scalar keys %vertices_map);
+                }
+                $vertices_map{$#$vertices} = $unique_vertices{$key};
+            }
         } elsif (/^f (\d+).*? (\d+).*? (\d+).*?/) {
-            push @$facets, [ $1-1, $2-1, $3-1 ];
+            if (MERGE_DUPLICATE_VERTICES) {
+                push @$facets, [ map $vertices_map{$_}, $1-1, $2-1, $3-1 ];
+            } else {
+                push @$facets, [ $1-1, $2-1, $3-1 ];
+            }
+            push @$facets_materials, $cur_material_idx;
+        } elsif (/^usemtl (.+)/) {
+            $materials{$1} //= scalar(keys %materials);
+            $cur_material_idx = $materials{$1};
         }
     }
     close $fh;
     
     my $model = Slic3r::Model->new;
     my $object = $model->add_object(vertices => $vertices);
-    my $volume = $object->add_volume(facets => $facets);
+    my $volume = $object->add_volume(
+        facets           => $facets,
+        facets_materials => $facets_materials,
+        materials        => { reverse %materials },
+    );
+    $model->set_material($_) for keys %materials;use XXX; XXX $model;
     return $model;
 }
 
diff --git a/lib/Slic3r/Model.pm b/lib/Slic3r/Model.pm
index c05ee8ee..31d5657e 100644
--- a/lib/Slic3r/Model.pm
+++ b/lib/Slic3r/Model.pm
@@ -142,12 +142,18 @@ use Moo;
 has 'object'        => (is => 'ro', weak_ref => 1, required => 1);
 has 'material_id'   => (is => 'rw');
 has 'facets'        => (is => 'rw', default => sub { [] });
+has 'facets_materials' => (is => 'rw', default => sub { [] });   # facet_idx => material_idx
+
+# maps the material numeric index used in the facets hashref to the alphanumeric model-wise material_id
+has 'materials'     => (is => 'rw', default => sub { [] });     # material_idx => material_id
 
 sub mesh {
     my $self = shift;
     return Slic3r::TriangleMesh->new(
         vertices => $self->object->vertices,
         facets   => $self->facets,
+        facets_materials => $self->facets_materials,
+        materials        => $self->materials,
     );
 }
 
diff --git a/lib/Slic3r/TriangleMesh.pm b/lib/Slic3r/TriangleMesh.pm
index 0f5df9a4..eb210d9c 100644
--- a/lib/Slic3r/TriangleMesh.pm
+++ b/lib/Slic3r/TriangleMesh.pm
@@ -7,6 +7,8 @@ use Slic3r::Geometry::Clipper qw(union_ex);
 # public
 has 'vertices'      => (is => 'ro', required => 1);         # id => [$x,$y,$z]
 has 'facets'        => (is => 'ro', required => 1);         # id => [ $v1_id, $v2_id, $v3_id ]
+has 'materials'     => (is => 'ro', default => sub { [] }); # material_idx => material_id
+has 'facets_materials' => (is => 'ro');                     # facet_idx => material_idx
 
 # private
 has 'edges'         => (is => 'ro', default => sub { [] }); # id => [ $v1_id, $v2_id ]