OpenWalnut
1.4.0
|
00001 //--------------------------------------------------------------------------- 00002 // 00003 // Project: OpenWalnut ( http://www.openwalnut.org ) 00004 // 00005 // Copyright 2009 OpenWalnut Community, BSV@Uni-Leipzig and CNCF@MPI-CBS 00006 // For more information see http://www.openwalnut.org/copying 00007 // 00008 // This file is part of OpenWalnut. 00009 // 00010 // OpenWalnut is free software: you can redistribute it and/or modify 00011 // it under the terms of the GNU Lesser General Public License as published by 00012 // the Free Software Foundation, either version 3 of the License, or 00013 // (at your option) any later version. 00014 // 00015 // OpenWalnut is distributed in the hope that it will be useful, 00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00018 // GNU Lesser General Public License for more details. 00019 // 00020 // You should have received a copy of the GNU Lesser General Public License 00021 // along with OpenWalnut. If not, see <http://www.gnu.org/licenses/>. 00022 // 00023 //--------------------------------------------------------------------------- 00024 00025 #ifndef WGEGROUPNODE_H 00026 #define WGEGROUPNODE_H 00027 00028 #include <queue> 00029 00030 #include <boost/thread.hpp> 00031 00032 #include <osg/MatrixTransform> 00033 #include <osg/NodeCallback> 00034 00035 #include "../common/WPredicateHelper.h" 00036 00037 00038 /** 00039 * Class to wrap around the osg Group node and providing a thread safe add/removal mechanism. Please be sure to use 00040 * addUpdateCallback() to set your own update callbacks instead of setUpdateCallback, as this class already has set a callback, 00041 * which would be overwritten by a subsequent call to setUpdateCallback(). It is derived from osg::MatrixTransform to allow easy transformations 00042 * of a whole bunch of nodes. 00043 * 00044 * \ingroup GE 00045 */ 00046 class WGEGroupNode: public osg::MatrixTransform 00047 { 00048 public: 00049 /** 00050 * Default constructor. 00051 */ 00052 WGEGroupNode(); 00053 00054 /** 00055 * Adds the specified node to the child list of this node in a safe manner. OSG officially requires nodes to be added 00056 * exclusively during update callbacks. Using this method it is ensured to be added during update cycle. 00057 * 00058 * \param node the node to add. 00059 * 00060 * \note the node may not be added instantly. So do not assume that containsNode ( node ) will return true. 00061 */ 00062 void insert( osg::ref_ptr< osg::Node > node ); 00063 00064 /** 00065 * Removes the specified node from this group in a thread safe manner. It returns if the node has been removed. 00066 * 00067 * \param node the node to remove 00068 */ 00069 void remove( osg::ref_ptr< osg::Node > node ); 00070 00071 /** 00072 * The base type of predicate. Use a specific WPredicateHelper::ArbitraryPredicate instance. For details, see 00073 * \ref WPredicateHelper::ArbitraryPredicateBase. 00074 */ 00075 typedef WPredicateHelper::ArbitraryPredicateBase< osg::ref_ptr< osg::Node > const > NodePredicate; 00076 00077 /** 00078 * Removes a node if the specified predicate evaluates to true. 00079 * \see WPredicateHelper::ArbitraryPredicate for details. 00080 * 00081 * \param predicate the predicate. 00082 */ 00083 void remove_if( boost::shared_ptr< WGEGroupNode::NodePredicate > predicate ); 00084 00085 /** 00086 * Removes all children from this node. 00087 */ 00088 void clear(); 00089 00090 protected: 00091 /** 00092 * Destructor. 00093 */ 00094 virtual ~WGEGroupNode(); 00095 00096 /** 00097 * Update callback which inserts and removes nodes from m_childRemovalQueue and m_childInsertionQueue to the group node. 00098 * This ensures thread safe modification of the osg root node. 00099 */ 00100 class SafeUpdaterCallback : public osg::NodeCallback 00101 { 00102 public: 00103 /** 00104 * Callback method called by the NodeVisitor when visiting a node. 00105 * This inserts and removes enqueued nodes from this group node instance. 00106 * 00107 * \param node the node calling this update 00108 * \param nv The node visitor which performs the traversal. Should be an 00109 * update visitor. 00110 */ 00111 virtual void operator()( osg::Node* node, osg::NodeVisitor* nv ); 00112 }; 00113 00114 /** 00115 * Node callback used to update this root node. 00116 */ 00117 osg::ref_ptr< SafeUpdaterCallback > m_nodeUpdater; 00118 00119 /** 00120 * The type of operation to perform. 00121 */ 00122 typedef enum 00123 { 00124 INSERT = 0, //! insert the specified node 00125 REMOVE, //! remove the specified node 00126 REMOVE_IF, //! remove all items where the predicate evaluates to true 00127 CLEAR //! clear group node completely 00128 } 00129 ChildOperationType; 00130 00131 /** 00132 * A struct denoting an operation on this group. The operation itself, as well as the item and predicate are stored. 00133 */ 00134 struct ChildOperation 00135 { 00136 /** 00137 * Constructs instance and fills members properly. 00138 * 00139 * \param what the operation to make 00140 * \param item the child to delete 00141 */ 00142 ChildOperation( ChildOperationType what, osg::ref_ptr< osg::Node > item ): 00143 m_operation( what ), 00144 m_item( item ), 00145 m_predicate() 00146 { 00147 }; 00148 00149 /** 00150 * Constructs instance and fills members properly. 00151 * 00152 * \param what the operation to make 00153 * \param predicate the predicate to use for conditional operations (REMOVE_IF) 00154 */ 00155 ChildOperation( ChildOperationType what, boost::shared_ptr< NodePredicate > predicate ): 00156 m_operation( what ), 00157 m_item(), 00158 m_predicate( predicate ) 00159 { 00160 }; 00161 00162 ChildOperationType m_operation; //!< the operation to take 00163 osg::ref_ptr< osg::Node > m_item; //!< the item to delete/add 00164 boost::shared_ptr< NodePredicate > m_predicate; //!< the predicate used by conditional operations 00165 }; 00166 00167 /** 00168 * Queue of childs that need to be added/removed during the next update cycle. It is a pair per operation, where the bool is denoting removal 00169 * or insertion. 00170 */ 00171 std::queue< boost::shared_ptr< ChildOperation > > m_childOperationQueue; 00172 00173 /** 00174 * Lock used for inserting and removing childs into the child insertion/removal queue. 00175 */ 00176 boost::shared_mutex m_childOperationQueueLock; 00177 00178 /** 00179 * Flag denoting whether the m_childOperationQueue should be considered during the next update of the node. 00180 */ 00181 bool m_childOperationQueueDirty; 00182 00183 /** 00184 * True whenever all child nodes should be removed. 00185 */ 00186 bool m_removeAll; 00187 00188 private: 00189 }; 00190 00191 #endif // WGEGROUPNODE_H 00192