libosgearth-dev 2.5.0+dfsg-8build1 / usr / include / osgEarth / NodeUtils

/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2013 Pelican Mapping
* http://osgearth.org
*
* osgEarth is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>
*/
#ifndef OSGEARTH_NODE_UTILS_H
#define OSGEARTH_NODE_UTILS_H 1

#include <osgEarth/Common>
#include <osg/View>
#include <osg/PagedLOD>
#include <osgGA/GUIActionAdapter>
#include <osgUtil/LineSegmentIntersector>
#include <osgEarth/ThreadingUtils>
#include <set>
#include <vector>

namespace osgEarth
{
    /**
     * General purpose operation for doing something to a node.
     */
    struct NodeOperation : public osg::Referenced
    {
        virtual void operator()( osg::Node* node ) =0;
    };

    typedef std::vector< osg::ref_ptr<NodeOperation> > NodeOperationVector;

    struct RefNodeOperationVector : public osg::Referenced, public NodeOperationVector { };

    /**
     * A PagedLOD that will fire node operation callbacks when it merges
     * new nodes into the graph.
     */
    class OSGEARTH_EXPORT PagedLODWithNodeOperations : public osg::PagedLOD
    {
    public:
        PagedLODWithNodeOperations( RefNodeOperationVector* postMergeOps );

    public: // osg::Group

        virtual bool addChild( osg::Node* child );
        virtual bool insertChild( unsigned index, Node* child );
        virtual bool replaceChild( Node* origChild, Node* newChild );

    protected:
        osg::observer_ptr<RefNodeOperationVector> _postMergeOps;
        
        void runPostMerge( osg::Node* node );
    };

    /**
     * Visitor that looks for empty group nodes and removes them from the 
     * scene graph. (Note, if the entry node is an empty group, it will
     * not be affected.)
     */
    class OSGEARTH_EXPORT RemoveEmptyGroupsVisitor : public osg::NodeVisitor
    {
    public:
        static void run( osg::Node* entry ) {
            if ( entry ) {
                RemoveEmptyGroupsVisitor v;
                entry->accept( v );
            }
        }

    public:
        RemoveEmptyGroupsVisitor();
        void apply( osg::Group& group ); //override
    };

    /**
     * Visitor that counts the number of point, line, and polygon primitive sets
     * in a scene graph.
     */
    class OSGEARTH_EXPORT PrimitiveSetTypeCounter : public osg::NodeVisitor
    {
    public:
        PrimitiveSetTypeCounter();

        /** dtor */
        virtual ~PrimitiveSetTypeCounter() { }

        void apply(class osg::Geode&);

        unsigned _point;
        unsigned _line;
        unsigned _polygon;
    };

    /**
     * Visitor that finds all the parental Camera Views, and calls an operator
     * on each one.
     */
    template<typename T>
    class ViewVisitor : public osg::NodeVisitor, public T
    {
    public:
        ViewVisitor() : osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_PARENTS) { }
        virtual ~ViewVisitor() { }
        void apply(osg::Camera& cam) {
            osg::View* view = cam.getView();
            if ( view ) this->operator()( view );
            traverse(cam);
        }
    };

    /**
     * Functor (for use with ViewVisitor) that notifies a view that it needs to
     * redraw the scene because something has changed
     * Usage: ViewVisitor<RequestRedraw> vis; node->accept(vis);
     */
    struct RequestRedraw 
    {
        void operator()(osg::View* view) {
            osgGA::GUIActionAdapter* aa = dynamic_cast<osgGA::GUIActionAdapter*>(view);
            if ( aa ) aa->requestRedraw();
        }
    };

    /**
     * Visitor that locates a node by its type
     */
    template<typename T>
    class FindTopMostNodeOfTypeVisitor : public osg::NodeVisitor
    {
    public:
        FindTopMostNodeOfTypeVisitor():
          osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
              _foundNode(0)
          {}

          void apply(osg::Node& node)
          {
              T* result = dynamic_cast<T*>(&node);
              if (result)
              {
                  _foundNode = result;
              }
              else
              {
                  traverse(node);
              }
          }

          T* _foundNode;
    };

    /** 
     * Collects all the nodes of type "T"
     */
    template<typename T>
    struct FindNodesVisitor : public osg::NodeVisitor
    {
        FindNodesVisitor() : osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) { }

        void apply(osg::Node& node)
        {
            T* result = dynamic_cast<T*>( &node );
            if ( result )
                _results.push_back( result );
            traverse(node);
        }

        std::vector<T*> _results;
    };

    /**
     * Searchs the scene graph downward starting at [node] and returns the first node found
     * that matches the template parameter type.
     */
    template<typename T>
    T* findTopMostNodeOfType(osg::Node* node, unsigned traversalMask =~0)
    {
        if (!node) return 0;

        FindTopMostNodeOfTypeVisitor<T> fnotv;
        fnotv.setTraversalMode(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN);
        fnotv.setTraversalMask(traversalMask);
        node->accept(fnotv);

        return fnotv._foundNode;
    }    

    /**
     * Searchs the scene graph upward starting at [node] and returns the first node found
     * that matches the template parameter type.
     */
    template<typename T>
    T* findFirstParentOfType(osg::Node* node, unsigned traversalMask =~0)
    {
        if (!node) return 0;

        FindTopMostNodeOfTypeVisitor<T> fnotv;
        fnotv.setTraversalMode(osg::NodeVisitor::TRAVERSE_PARENTS);
        fnotv.setTraversalMask(traversalMask);
        node->accept(fnotv);

        return fnotv._foundNode;
    }

    /**
     * Searchs the scene graph starting at [node] and returns the first node found
     * that matches the template parameter type. First searched upward, then downward.
     */
    template<typename T>
    T* findRelativeNodeOfType(osg::Node* node, unsigned traversalMask =~0)
    {
        if ( !node ) return 0;
        T* result = findFirstParentOfType<T>( node, traversalMask );
        if ( !result )
            result = findTopMostNodeOfType<T>( node, traversalMask );
        return result;
    }

    /**
     * Replace one group with another
     */
    inline void replaceGroup( osg::Group* oldGroup, osg::Group* newGroup )
    {
        if ( oldGroup && newGroup && oldGroup->getNumParents() > 0 )
        {
            for(unsigned i=0; i<oldGroup->getNumChildren(); ++i)
            {
                newGroup->addChild( oldGroup->getChild(0) );
            }

            osg::Node::ParentList parents = oldGroup->getParents();
            for(osg::Node::ParentList::iterator i = parents.begin(); i != parents.end(); ++i )
            {
                (*i)->replaceChild( oldGroup, newGroup );
            }
        }
    }

    /**
     * Remove all a group's children.
     */
    inline void clearChildren( osg::Group* group )
    {
        if ( group )
            group->removeChildren( 0, group->getNumChildren() );
    }

    /**
     * OSG Group that keeps its children as observer_ptrs instead of ref_ptrs, and
     * removes them when they deref.
     */
    class OSGEARTH_EXPORT ObserverGroup : public osg::Group
    {
    public:
        ObserverGroup();
        virtual void traverse( osg::NodeVisitor& nv );
        std::set<osg::Node*> _orphans;
    };

    
    /**
     * Group that acts like a normal group but also notifies another
     * object when a change occurs.
     */
    template<typename T>
    class NotifierGroup : public osg::Group
    {
    public:
        NotifierGroup(T* listener) : _listener(listener) { }

        virtual bool addChild( osg::Node* child ) {
            bool ok = osg::Group::addChild(child);
            if ( ok && _listener.valid() ) _listener->onGroupChanged(this);
            return ok;
        }
        virtual bool insertChild( unsigned index, osg::Node* child ) {
            bool ok = osg::Group::insertChild(index, child);
            if ( ok && _listener.valid() ) _listener->onGroupChanged(this);
            return ok;
        }
        virtual bool removeChild( osg::Node* child ) {
            bool ok = osg::Group::removeChild( child );
            if ( ok && _listener.valid() ) _listener->onGroupChanged(this);
            return ok;
        }
        virtual bool replaceChild( osg::Node* origChild, osg::Node* newChild ) {
            bool ok = osg::Group::replaceChild(origChild, newChild);
            if ( ok && _listener.valid() ) _listener->onGroupChanged(this);
            return ok;
        }

    protected:
        virtual ~NotifierGroup() { }
        osg::observer_ptr<T> _listener;
    };


    /**
     * Adjusts a node's update traversal count by a delta.
     * Only safe to call from the UPDATE thread
     */
#define ADJUST_UPDATE_TRAV_COUNT( NODE, DELTA ) \
    { \
        int oldCount = NODE ->getNumChildrenRequiringUpdateTraversal(); \
        if ( oldCount + DELTA >= 0 ) \
            NODE ->setNumChildrenRequiringUpdateTraversal( (unsigned int)(oldCount + DELTA ) ); \
    }

    /**
     * Adjusts a node's event traversal count by a delta.
     * Only safe to call from the main/event/update threads
     */
#define ADJUST_EVENT_TRAV_COUNT( NODE, DELTA ) \
    { \
        int oldCount = NODE ->getNumChildrenRequiringEventTraversal(); \
        if ( oldCount + DELTA >= 0 ) \
            NODE ->setNumChildrenRequiringEventTraversal( (unsigned int)(oldCount + DELTA ) ); \
    }
}

#endif // OSGEARTH_CACHING_H