3mf Exporter - 1st installment

xs/src/libslic3r/Format/3mf.hpp

@@ -5,8 +5,12 @@ namespace Slic3r {
 
     class Model;
 
-    // Load an 3mf file into a provided model.
-    extern bool load_3mf(const char* path, Model* model, const char* object_name = nullptr);
+    // Load a 3mf file into the given model.
+    extern bool load_3mf(const char* path, Model* model);
+
+    // Save the given model into a 3mf file.
+    // The model could be modified during the export process if meshes are not repaired or have no shared vertices
+    extern bool store_3mf(const char* path, Model* model);
 }; // namespace Slic3r
 
 #endif /* slic3r_Format_3mf_hpp_ */