Rendering seams (and other options) in preview using batched models on systems not supporting OpenGL 3.3

src/slic3r/GUI/GLModel.hpp

@@ -48,6 +48,15 @@ namespace GUI {
             };
 
             std::vector<Entity> entities;
+
+#if ENABLE_SEAMS_USING_BATCHED_MODELS
+            size_t vertices_count() const;
+            size_t vertices_size_floats() const { return vertices_count() * 6; }
+            size_t vertices_size_bytes() const { return vertices_size_floats() * sizeof(float); }
+
+            size_t indices_count() const;
+            size_t indices_size_bytes() const { return indices_count() * sizeof(unsigned int); }
+#endif // ENABLE_SEAMS_USING_BATCHED_MODELS
         };
 
     private: