Make loading of obj files into TriangleMesh possible.

src/libslic3r/Format/OBJ.cpp

@@ -15,12 +15,14 @@
 
 namespace Slic3r {
 
-bool load_obj(const char *path, Model *model, const char *object_name_in)
+bool load_obj(const char *path, TriangleMesh *meshptr)
 {
+    if(meshptr == nullptr) return false;
+    
     // Parse the OBJ file.
     ObjParser::ObjData data;
     if (! ObjParser::objparse(path, data)) {
-//    die "Failed to parse $file\n" if !-e $path;
+        //    die "Failed to parse $file\n" if !-e $path;
         return false;
     }
     
@@ -44,10 +46,10 @@ bool load_obj(const char *path, Model *model, const char *object_name_in)
     }
     
     // Convert ObjData into STL.
-    TriangleMesh mesh;
+    TriangleMesh &mesh = *meshptr;
     stl_file &stl = mesh.stl;
     stl.stats.type = inmemory;
-    stl.stats.number_of_facets = int(num_faces + num_quads);
+    stl.stats.number_of_facets = uint32_t(num_faces + num_quads);
     stl.stats.original_num_facets = int(num_faces + num_quads);
     // stl_allocate clears all the allocated data to zero, all normals are set to zeros as well.
     stl_allocate(&stl);
@@ -100,10 +102,20 @@ bool load_obj(const char *path, Model *model, const char *object_name_in)
     stl_get_size(&stl);
     mesh.repair();
     if (mesh.facets_count() == 0) {
-        // die "This STL file couldn't be read because it's empty.\n"
+        // die "This OBJ file couldn't be read because it's empty.\n"
         return false;
     }
     
+    return true;
+}
+
+bool load_obj(const char *path, Model *model, const char *object_name_in)
+{
+    TriangleMesh mesh;
+    
+    bool ret = load_obj(path, &mesh);
+    
+    if (ret) {
         std::string  object_name;
         if (object_name_in == nullptr) {
             const char *last_slash = strrchr(path, DIR_SEPARATOR);
@@ -112,7 +124,9 @@ bool load_obj(const char *path, Model *model, const char *object_name_in)
            object_name.assign(object_name_in);
     
         model->add_object(object_name.c_str(), path, std::move(mesh));
-    return true;
+    }
+    
+    return ret;
 }
 
 bool store_obj(const char *path, TriangleMesh *mesh)

src/libslic3r/Format/OBJ.hpp

@@ -5,8 +5,10 @@ namespace Slic3r {
 
 class TriangleMesh;
 class Model;
+class ModelObject;
 
 // Load an OBJ file into a provided model.
+extern bool load_obj(const char *path, TriangleMesh *mesh);
 extern bool load_obj(const char *path, Model *model, const char *object_name = nullptr);
 
 extern bool store_obj(const char *path, TriangleMesh *mesh);