GltfSerializer: opt-in --gltf-extras with GlobalId, type and name

Issue #790 asked for IFC metadata in glTF node extras so the glb is
self-describing. Off by default to keep file size unchanged, per the
maintainer's concern about embedding data; the flag writes GlobalId,
entity type and Name on every node, including hierarchy group nodes.

Generated with the assistance of an AI coding tool.

src/ifcgeom/GeometrySerializer.h

@@ -68,6 +68,13 @@ inline namespace settings {
 		static constexpr bool defaultvalue = false;
 	};
 
+	struct GltfExtras : public SettingBase<GltfExtras, bool> {
+		static constexpr const char* const name = "gltf-extras";
+		static constexpr const char* const description = "Write the IFC GlobalId, entity type and name of every element into the "
+			"glTF node extras, so the output is self-describing without a sidecar file. Applicable to GLB output.";
+		static constexpr bool defaultvalue = false;
+	};
+
 	struct FloatingPointDigits : public SettingBase<FloatingPointDigits, int> {
 		static constexpr const char* const name = "digits";
 		static constexpr const char* const description = "Sets the precision to be used to format floating-point values, 15 by default. "
@@ -97,7 +104,7 @@ inline namespace settings {
 
 class SerializerSettings : public SettingsContainer <
 	// @todo should we use tuple_cat here to unify the settings into a single class?
-    std::tuple<UseElementNames, UseElementGuids, UseElementStepIds, UseElementTypes, UseYUp, WriteGltfEcef, FloatingPointDigits, BaseUri, WktUseSection, SeparateZUpNode>>
+    std::tuple<UseElementNames, UseElementGuids, UseElementStepIds, UseElementTypes, UseYUp, WriteGltfEcef, GltfExtras, FloatingPointDigits, BaseUri, WktUseSection, SeparateZUpNode>>
 {};
 
 }

src/serializers/GltfSerializer.cpp

@@ -249,7 +249,10 @@ void GltfSerializer::write(const IfcGeom::TriangulationElement* o) {
             size_t new_node_index = json_["nodes"].size();
             node_indices_[(*it)->product()] = new_node_index;
             node_array_.push_back(new_node_index);
-            parent_node["name"] = object_id(o);
+            parent_node["name"] = object_id(*it);
+            if (settings_.get<ifcopenshell::geometry::settings::GltfExtras>().get()) {
+                parent_node["extras"] = { {"GlobalId", (*it)->guid()}, {"IfcType", (*it)->type()}, {"Name", (*it)->name()} };
+            }
             parent_node["children"] = json::array({current_node_index});
             json_["nodes"].push_back(parent_node);
 
@@ -290,7 +293,10 @@ void GltfSerializer::write(const IfcGeom::TriangulationElement* o) {
 		}
 	}
 	node["name"] = object_id(o);
-	
+	if (settings_.get<ifcopenshell::geometry::settings::GltfExtras>().get()) {
+		node["extras"] = { {"GlobalId", o->guid()}, {"IfcType", o->type()}, {"Name", o->name()} };
+	}
+
 	int current_mesh_index;
 
 	// See if this mesh has already been processed