Port the OBJ parser to C++

lib/Slic3r/Format/OBJ.pm

@@ -1,33 +1,12 @@
 package Slic3r::Format::OBJ;
 use Moo;
 
-use File::Basename qw(basename);
-
 sub read_file {
     my $self = shift;
     my ($file) = @_;
     
-    Slic3r::open(\my $fh, '<', $file) or die "Failed to open $file\n";
-    my $vertices = [];
-    my $facets = [];
-    while (<$fh>) {
-        if (/^v ([^ ]+)\s+([^ ]+)\s+([^ ]+)/) {
-            push @$vertices, [$1, $2, $3];
-        } elsif (/^f (\d+).*? (\d+).*? (\d+).*?/) {
-            push @$facets, [ $1-1, $2-1, $3-1 ];
-        }
-    }
-    close $fh;
-    
-    my $mesh = Slic3r::TriangleMesh->new;
-    $mesh->ReadFromPerl($vertices, $facets);
-    $mesh->check_topology;
-    
     my $model = Slic3r::Model->new;
-    
-    my $basename = basename($file);
-    my $object = $model->add_object(input_file => $file, name => $basename);
-    my $volume = $object->add_volume(mesh => $mesh, name => $basename);
+    $model->read_obj($file);
     return $model;
 }
 

xs/MANIFEST

@@ -117,6 +117,7 @@ src/slic3r/GUI/3DScene.cpp
 src/slic3r/GUI/3DScene.hpp
 src/slic3r/GUI/GUI.cpp
 src/slic3r/GUI/GUI.hpp
+src/tiny_obj_loader.h
 src/xsinit.h
 t/01_trianglemesh.t
 t/03_point.t

xs/src/libslic3r/IO.cpp

@@ -3,11 +3,17 @@
 #include <fstream>
 #include <iostream>
 
+#define TINYOBJLOADER_IMPLEMENTATION
+#include "tiny_obj_loader.h"
+
 namespace Slic3r { namespace IO {
 
 bool
 STL::read(std::string input_file, TriangleMesh* mesh)
 {
+    // TODO: encode file name
+    // TODO: check that file exists
+    
     try {
         mesh->ReadSTLFile(input_file);
         mesh->check_topology();
@@ -20,9 +26,6 @@ STL::read(std::string input_file, TriangleMesh* mesh)
 bool
 STL::read(std::string input_file, Model* model)
 {
-    // TODO: encode file name
-    // TODO: check that file exists
-    
     TriangleMesh mesh;
     if (!STL::read(input_file, &mesh)) return false;
     
@@ -50,6 +53,77 @@ STL::write(TriangleMesh& mesh, std::string output_file, bool binary)
     return true;
 }
 
+bool
+OBJ::read(std::string input_file, TriangleMesh* mesh)
+{
+    Model model;
+    OBJ::read(input_file, &model);
+    *mesh = model.mesh();
+    
+    return true;
+}
+
+bool
+OBJ::read(std::string input_file, Model* model)
+{
+    // TODO: encode file name
+    // TODO: check that file exists
+    
+    tinyobj::attrib_t attrib;
+    std::vector<tinyobj::shape_t> shapes;
+    std::vector<tinyobj::material_t> materials;
+    std::string err;
+    bool ret = tinyobj::LoadObj(&attrib, &shapes, &materials, &err, input_file.c_str());
+    
+    if (!err.empty()) { // `err` may contain warning message.
+        std::cerr << err << std::endl;
+    }
+    
+    if (!ret)
+        throw std::runtime_error("Error while reading OBJ file");
+    
+    ModelObject* object = model->add_object();
+    object->name        = input_file;  // TODO: use basename()
+    object->input_file  = input_file;
+    
+    // Loop over shapes and add a volume for each one.
+    for (std::vector<tinyobj::shape_t>::const_iterator shape = shapes.begin();
+        shape != shapes.end(); ++shape) {
+        
+        Pointf3s points;
+        std::vector<Point3> facets;
+        
+        // Read vertices.
+        assert((shape->mesh.vertices.size() % 3) == 0);
+        for (size_t v = 0; v < attrib.vertices.size(); ++v) {
+            points.push_back(Pointf3(
+                attrib.vertices[v],
+                attrib.vertices[++v],
+                attrib.vertices[++v]
+            ));
+        }
+        
+        // Loop over facets of the current shape.
+        for (size_t f = 0; f < shape->mesh.num_face_vertices.size(); ++f) {
+            // tiny_obj_loader should triangulate any facet with more than 3 vertices
+            assert((shape->mesh.num_face_vertices[f] % 3) == 0);
+            
+            facets.push_back(Point3(
+                shape->mesh.indices[f*3+0].vertex_index,
+                shape->mesh.indices[f*3+1].vertex_index,
+                shape->mesh.indices[f*3+2].vertex_index
+            ));
+        }
+        
+        TriangleMesh mesh(points, facets);
+        mesh.check_topology();
+        ModelVolume* volume = object->add_volume(mesh);
+        volume->name        = input_file;   // TODO: use basename()
+    }
+    
+    return true;
+}
+
 bool
 OBJ::write(TriangleMesh& mesh, std::string output_file)
 {

xs/src/libslic3r/IO.hpp

@@ -19,6 +19,8 @@ class STL
 class OBJ
 {
     public:
+    static bool read(std::string input_file, TriangleMesh* mesh);
+    static bool read(std::string input_file, Model* model);
     static bool write(TriangleMesh& mesh, std::string output_file);
 };
 

xs/xsp/Model.xsp

@@ -2,6 +2,7 @@
 
 %{
 #include <xsinit.h>
+#include "libslic3r/IO.hpp"
 #include "libslic3r/Model.hpp"
 #include "libslic3r/PrintConfig.hpp"
 %}
@@ -13,6 +14,9 @@
     Clone<Model> clone()
         %code%{ RETVAL = THIS; %};
     
+    bool read_obj(std::string input_file)
+        %code%{ RETVAL = Slic3r::IO::OBJ::read(input_file, THIS); %};
+    
     %name{_add_object} Ref<ModelObject> add_object();
     Ref<ModelObject> _add_object_clone(ModelObject* other, bool copy_volumes = true)
         %code%{ RETVAL = THIS->add_object(*other, copy_volumes); %};