Thanks Riccardo. I'm currently submerged in refactoring osgParticle, once this is completed I'll have a look at the modified osgcallback.cpp.
On 29 August 2016 at 16:20, Riccardo Corsi <[email protected]> wrote: > Hi Robert, > > please find attached a simple example that shows the issues I was trying to > explain: > - launch with no args to see the initial issue > - launch with "--crash" to get the crash i ran into when implementing the > callback deriving from osg::Callback > - launch with "--fix" to see the way I fixed it with the NodeCallback: > comments on the run() and operator() methods explain some concerns for this > solution > > Hope this clarifies things :) > Ricky > > > On Mon, Aug 29, 2016 at 4:29 PM, Robert Osfield <[email protected]> > wrote: >> >> Hi Ricky, >> >> The changes to Drawable and the knock on effect to the callbacks is an >> awkward one - it would be easy if it we could just discard backwards >> compatibility, so it's a far from ideal code, but alas you can't >> rewrite history once it's happened. >> >> From your description I don't have a clear idea of what is being >> called twice and whether this is a problem. Could you create a small >> example that illustrates the problem, once I can see first hand I can >> review the behaviour and decide whether this is acceptable or is an >> bug. >> >> Thanks, >> Robert. >> >> On 29 August 2016 at 15:00, Riccardo Corsi <[email protected]> >> wrote: >> > Hi all, >> > >> > I report what I believe could be considered a bug, probably introduced >> > after >> > the promotion of the Drawable class to a node, together with the new >> > callback system. >> > >> > I have a GUIEventHandler derived class installed on a Drawable. >> > After some digging I've realized that it's called twice for every event >> > due >> > to the EventVisitor code here: >> > >> > https://github.com/openscenegraph/OpenSceneGraph/blob/master/include/osgGA/EventVisitor#L86 >> > >> > GUIEventHandler happens to derive both from NodeCallback and >> > DrawableEventCallback, resulting in it being called twice. I think this >> > might be considered as a bug if the intended behavior was to keep using >> > the >> > old GUIEventHandler interface the way it was (when attached to the >> > viewer >> > for instance, it is called only once as expected). >> > >> > Relate issue: >> > I've re-implemented my callback deriving from osg::Callback, but this >> > results in a crash as the osg::CallbackObject interface is used even if >> > the >> > cast does not succeed (first if condition) >> > >> > https://github.com/openscenegraph/OpenSceneGraph/blob/master/include/osgGA/EventVisitor#L93 >> > >> > I fixed that by deriving from osg::NodeCallback, but I had to >> > reimplement >> > the operator() method instead of run(), as the second is not called by >> > the >> > visitor - that also it's a bit counter-intuitive with respect to the >> > osg::Callback class interface. >> > >> > Ricky >> > >> > >> > >> > >> > >> > >> > >> > _______________________________________________ >> > osg-users mailing list >> > [email protected] >> > >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
