void Terrain::traverse(osg::NodeVisitor &nv)
{
if (nv.getVisitorType() == osg::NodeVisitor::UPDATE_VISITOR)
{
// need to check if any TerrainTechniques need to have their update called on them.
osgUtil::UpdateVisitor *uv = dynamic_cast<osgUtil::UpdateVisitor*>(&nv);
if (uv)
{
typedef std::list<osg::ref_ptr<TerrainTile> > TerrainTileList;
TerrainTileList tiles;
{
OpenThreads::ScopedLock<OpenThreads::ReentrantMutex> lock(_mutex);
for (TerrainTileSet::iterator itr = _updateTerrainTileSet.begin(); itr != _updateTerrainTileSet.end(); ++itr)
{
// take a reference first to make sure that the referenceCount can be safely read without another thread decrementing it to zero.
(*itr)->ref();
// only if referenceCount is 2 or more indicating there is still a reference held elsewhere is it safe to add it to list of tiles to be updated
if ((*itr)->referenceCount() > 1)
tiles.push_back(*itr);
// use unref_nodelete to avoid any issues when the *itr TerrainTile has been deleted by another thread while this for loop has been running.
(*itr)->unref_nodelete();
}
_updateTerrainTileSet.clear();
}
for (TerrainTileList::iterator itr = tiles.begin();
itr != tiles.end();
++itr)
{
TerrainTile *tile = itr->get();
tile->traverse(nv);
}
}
}
if (nv.getVisitorType() == osg::NodeVisitor::CULL_VISITOR)
{
osgUtil::CullVisitor *cv = dynamic_cast<osgUtil::CullVisitor*>(&nv);
osg::StateSet *ss = _geometryPool.valid() ? _geometryPool->getRootStateSetForTerrain(this) : 0;
if (cv && ss)
{
cv->pushStateSet(ss);
Group::traverse(nv);
cv->popStateSet();
return;
}
}
Group::traverse(nv);
}
void Terrain::traverse(osg::NodeVisitor& nv)
{
if (nv.getVisitorType()==osg::NodeVisitor::UPDATE_VISITOR)
{
// need to check if any TerrainTechniques need to have their update called on them.
osgUtil::UpdateVisitor* uv = dynamic_cast<osgUtil::UpdateVisitor*>(&nv);
if (uv)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
for(TerrainTileSet::iterator itr = _updateTerrainTileSet.begin();
itr != _updateTerrainTileSet.end();
++itr)
{
TerrainTile* tile = *itr;
tile->traverse(nv);
}
_updateTerrainTileSet.clear();
}
}
Group::traverse(nv);
}