inline RenderLeaf* CullVisitor::createOrReuseRenderLeaf(osg::Drawable* drawable,osg::RefMatrix* projection,osg::RefMatrix* matrix, float depth)
{
// Skips any already reused renderleaf.
while (_currentReuseRenderLeafIndex<_reuseRenderLeafList.size() &&
_reuseRenderLeafList[_currentReuseRenderLeafIndex]->referenceCount()>1)///循环一次，找到没有被引用的渲染叶指针,通过引用计数判断
{
osg::notify(osg::NOTICE)<<"Warning:createOrReuseRenderLeaf() skipping multiply refrenced entry."<< std::endl;
++_currentReuseRenderLeafIndex;
}
// If still within list, element must be singularly referenced then return it to be reused.
if (_currentReuseRenderLeafIndex<_reuseRenderLeafList.size())//如果找到，则不需要产生新的
{
RenderLeaf* renderleaf = _reuseRenderLeafList[_currentReuseRenderLeafIndex++].get();
renderleaf->set(drawable,projection,matrix,depth);
return renderleaf;
}
// Otherwise need to create new renderleaf.
RenderLeaf* renderleaf = new RenderLeaf(drawable,projection,matrix,depth);//否则产生新的渲染叶
_reuseRenderLeafList.push_back(renderleaf);
++_currentReuseRenderLeafIndex;
return renderleaf;
}