Hi Michael, osgGA knows about core osg wher osg::View is defined, so could this work?
Robert. On 10/4/07, Michael Wittman <[EMAIL PROTECTED]> wrote: > Hi Robert, > > On Wed, Oct 03, 2007 at 09:11:21AM +0100, Robert Osfield wrote: > > On 10/3/07, Michael Wittman <[EMAIL PROTECTED]> wrote: > > > It's possible to add support to osgDotNet for upcasts along non-leftmost > > > inheritance branches. But downcasting in the same situation is a much > > > harder problem, and I don't know of a good solution for it at the moment. > > > > Perhaps we could add a GUIActionAdapter:asView() virtual function that > > returns a osg::View pointer. > > > > Another possibility would be to have a asViewer() and > > asCompositeViewer() methods too, but we'd have to forward declare > > osgViewer::Viewer and osgViewer::CompositeViewer to achieve this. I'm > > not sure what the consequences for the wrappers would be with this > > though. > > Unfortunately I don't think those approaches would help, as there's no > analogue to C++'s incomplete types in the CLR. And having knowledge of > full osgViewer wrapper types in the osgGA wrappers would necessitate a > circular dependency between the two assemblies, which is not permitted > (nor wise, in any case). > > I'm not entirely sure it would work, but best approach I can think of > would be implemented completely within the wrappers. It would involve > a registry of downcast conversion functions for every inheriting type > from all the types in its inheritance tree, indexed off the CLR's > type IDs for the inheriting and inherited types. A separate function > would then be provided to index into the registry and apply the correct > conversion function based on the CLR type IDs. The invoking code would > look something like this: > > OsgGA.GUIActionAdapter aa; > OsgViewer.Viewer v = OsgWrapper.Convert.Downcast(aa.GetType(), > typeof(OsgViewer.Viewer)) as OsgViewer.Viewer; > > One thing that's not clear to me currently is how to reliably construct > a unified conversion function registry across multiple wrapper assemblies. > > -Mike > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
