HI Paul, There isn't a convinience method for getting the current state inherited down to a node. The CullVisitor doesn't do it, its actually the draw traversal which does the actual accumulation of state via the osg::State class. The Optimizer doesn't do it either.
To implement it you'll need the a stack of StateSet from root the drawable leaf. One could try and use osg::State for this purpose, but it would be inefficient as it'll accumulate all state not just one particular mode or attribute. Robert. On 7/26/07, Paul Martz <[EMAIL PROTECTED]> wrote: > > > Hi Robert -- I'm trying to find the best way to get a snapshot of current > State at any given Node as it is traversed by some NodeVisitor. In other > words, within apply(Node&) of my custom NodeVisitor, I'd like to know if > current State would have, for example, polygon offset enabled or disabled. > > This seems like a common enough operation. CullVisitor must do it, and I > imagine Optimizer also has a need to track state. Yet there doesn't seem to > be a "StateVisitor" that I can use off the shelf for this purpose. > > I see CullVisitor uses the State class internally. This comes close to doing > what I need, but it seems more geared towards managing OpenGL state, rather > than simply tracking OSG state attributes and modes. (I can get the last > applied mode, for example, but I'm not applying a mode -- no current context > -- I just want to know what the current mode value is.) > > Seems like I can keep a stack of StateSets, and each time I hit a new node, > I push a copy onto the top of the stack and StateSet::merge() with the new > Node's StateSet. Oddly, merge() doesn't appear to support the PROTECTED mode > value (is this intentional?). > > Another method would be to essentially emulate what State does: keep a stack > for each mode and attribute, and push/modify then pop as appropriate. > However, I prefer the convenience of using merge(). > > Anyhow, I wondered if there was some other mechanism that I wasn't aware of > or hadn't considered yet. For example, is there some way to get an > accumulated StateSet given, say, a NodePath? > > Any info would be appreciated. > > (Posting at 20:20 UT July 26.) > > Paul Martz > Skew Matrix Software LLC > http://www.skew-matrix.com > 303 859 9466 > > _______________________________________________ > 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
