40 lines
1.8 KiB
Plaintext
40 lines
1.8 KiB
Plaintext
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/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
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*
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* This library is open source and may be redistributed and/or modified under
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* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
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* (at your option) any later version. The full license is in LICENSE file
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* included with this distribution, and on the openscenegraph.org website.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* OpenSceneGraph Public License for more details.
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*/
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#ifndef OSG_OCCLUDER
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#define OSG_OCCLUDER 1
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namespace osg {
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/** Observer base class for tracking when objects are unreferenced (there reference count goes to 0) and are being deleted.*/
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class Observer
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{
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public:
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virtual ~Observer() {}
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/** objectUnreferenced(void*) is called when the observed object's referenced count goes to zero, indicating that
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* the object will be deleted unless a new reference is made to it. If you wish to prevent deletion of the object
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* then it's reference count should be incremented such as via taking a ref_ptr<> to it, if no refernce is taken
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* by any of the observers of the object then the object will be deleted, and objectDeleted will in turn be called.
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* return true if the Observer wishes to removed from the oberseved objects observer set.*/
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virtual bool objectUnreferenced(void*) { return false; }
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/** objectDeleted is called when the observed object is about to be deleted. The observer will be automatically
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* removed from the observerd objects observer set so there is no need for the objectDeleted implementation
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* to call removeObserver() on the observed object. */
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virtual void objectDeleted(void*) {}
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};
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}
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#endif
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