Hi Grogoire, On Fri, Jun 10, 2011 at 2:58 PM, Gregoire Tarizzo <gregoire.tari...@virtuelcity.com> wrote: > As for me I have two main questions: > 1. This first question is not directly linked with the meta feature it's > just that i'm still very new to OSG and even more to serialization. How are > we going to serialize a custom type meta in our container? I've looked into > the UserDataContainer serializer, and I get that when it serializes the > _objectList, every object serialializer is called depending on the object > "type". But I still couldn't figure how and where I should specify the > proper serialization for a custom object.
I provide an example of serializer in the osguserdata example, and there are plenty of other examples of serializers in src/osgWrappers/serializes for all the core OSG classes. > 2. When I see the 3 diffent attributes in the UserDataContainer for > _userData, _descriptionList and _objectList, I don't know if there's > something awkward, or if I don't fully understand the issues. The _userData > and _desciptionList are, to me, meta values like any other meta value, so > why the special treatment? For backwards compatibility UserData is a osg::Referenced, you can't just assign it as a UserObject as this requires the Objects to be subclassed from osg::Object. You could in their have a custom Obect that holds the a ref_ptr<> for the UserData but this really would be an ungodly hack. In the case of the Descriptions list it's also backwards compatibility - you can fake compatibiity using a custom UserObject just for holding the Descriptions vector but it's a real hack to do so. So the approach I took actually has far less special treatment than the alternative, and fits very seamlessly in with the old API and it's usage. >It makes the UserDataContainer a little heavier > to have these three attributes instead of one std::vector. Couldn't we > imagine some kind of _userData and _desciptionList subclassing from Object? > Maybe this way we could make UserDataConainer inherit from std::vector > directly? Instead of being a container containing our real containers. The extra cost a ref_ptr<> and std::vector<std::string> is pretty small, and in normal usage I woudl expect only a small number of UserDataContainer objects to ever be created so this cost really is likely to be very small indeed. Given we have removed the std::vector<std::string> from osg::Node I would expect the new scheme to result in small scene graphs for everybody. Robert. _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
