Hello Brian,
I did not understand why down-casting is not possible. Super class can be downcasted to a concrete class through dynamic cast, isnt it? I am afraid that the discussion is getting a bit off -topic now. Sajjad On Thu, Apr 9, 2009 at 3:43 PM, Brian R Hill <bhil...@csc.com> wrote: > Sajjad, > > You can't cast a group to a switch if it wasn't created as a switch. > > osg::ref_ptr<osg::Group> groupOfLights; > > This will always fail and return 0. > osg::Switch * your_switch = dynamic_cast<osg::Switch *>(groupOfLights.get > ()); > > You need to create your groupOfLights as a switch. > > osg::ref_ptr<osg::Switch> groupOfLights; > > Since a switch is a groud, you can use it as both a group and a switch. > > Also, using dynamic_cast isn't bad. There are situations where it might not > be optimal. But for your intended use - key press events - it's absolutley > acceptable. > > Brian > > > This is a PRIVATE message. If you are not the intended recipient, please > delete without copying and kindly advise us by e-mail of the mistake in > delivery. > NOTE: Regardless of content, this e-mail shall not operate to bind CSC to > any order or other contract unless pursuant to explicit written agreement > or government initiative expressly permitting the use of e-mail for such > purpose. • > > > -----osg-users-boun...@lists.openscenegraph.org wrote: ----- > > > To: OpenSceneGraph Users <osg-users@lists.openscenegraph.org> > From: René Molenaar <megamillerz...@gmail.com> > Sent by: osg-users-boun...@lists.openscenegraph.org > Date: 04/09/2009 09:28AM > Subject: Re: [osg-users] Light Manager > > Hi Sajjad, > > > There are asType functions is osg::Node, > this has better performance then dynamic_cast ... > > for example you can do: > > osg::ref_ptr<osg::Switch> switch = group->asSwitch(); > > Now you are using a virtual table to get the right type: > > if the object is a Switch you will get the this-pointer of the Switch > if it is not you will get 0. > > Usually there are always better ways then dynamic_cast, especially > if you are the owner of the code. > > Good Luck, > > Rene > > > > > 2009/4/9 ami guru < dosto.wa...@gmail.com > > > Hello Forum, > > > I have a LightManager class that tracks the number of lights(OpenGL Lights) > that have been created. > > Inside the class the have the following member > > > osg::ref_ptr<osg::Group> groupOfLights; > vector<osg::ref_ptr<osg::LightSource> > lights; > > the member groupOfLights contain the LightSource as child. > > > In the application i want to select different light (spot,point or diffuse) > with key press event and only one light is enabled during an instant OR i > may enable several lights. > > > In that case i believe that i have to do dynamic casting to cast Group to > Switch. > > In other better way to do that ? > > > > Regards > Sajjad > > _______________________________________________ > 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 > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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