Hi Ulrich, Guten Rutsch ;-)
I've done a quick read of you proposal and it sounds good. For convenience perhaps adding a getIntProperty(), getFloatProperty() etc. methods might be appropriate, or perhaps one could use the bool getProperty(const std::string&, Property) interface that I adopted in osg::ArgumentParser, where Property is a temporary helper object. Robert. On Thu, Dec 31, 2009 at 11:22 AM, Ulrich Hertlein <[email protected]> wrote: > Hi guys, > > I have coded up a proposal for a general-purpose property system for > osg::Object and would > like to present it for comments and discussion. > > Properties must be derived from osg::Referenced and are stored in a map by > name: > > class PropertyMap : public Referenced, public std::map<std::string, > ref_ptr<Referenced> > > > - osg::Object has a 'osg::ref_ptr<osg::PropertyMap> _properties' > - this is only valid if there are any properties stored, so consumes minimal > memory. > - the properties map is created when a property is first added. > - for now it's never deleted but an explicit call for that could be added; it > could also > be deleted when the map becomes empty. > > - user data is stored/retrieved under the 'osg.data' name. The API is > unchanged. > - descriptions are stored/retrieved under the 'osg.desc' name. The API is > unchanged. > - 'osg::Object _userData' and 'osg::Node _descriptions' are removed. > > The general osg::Object API for properties is: > - void setProperty(const std::string& name, Referenced* prop); > - void clearProperty(name); > - const Referenced* getProperty(name) const; > - Referenced* getProperty(name); > > > For data that is not derived from osg::Referenced (like floats, int, strings) > instead of > using a variant class I've created the following template class: > > template <typename T> class Property : public Referenced { > public: > //... > void set(const T& data) { _data = data; } > const T& get() const { return _data; } > T& get() { return _data; } > > private: > T _data; > }; > > Data is stored like this: > osg::Property<int>* ip = new osg::Property<int>(42); > obj->setProperty("my.int", ip); > > and retrieved like this: > osg::Property<int>* ip0 = dynamic_cast<osg::Property<int> > >(obj->getProperty("my.int")); > ip0->get() == 42; > > > For convenience I've created template versions in osg::Object so that one can > write: > > obj->setProperty<int>("my.int", 42); // creates and stores Property<int>(42) > obj->getProperty<int>("my.int")->get() == 42; > (int) (*obj->getProperty<int>("my.int")) == 42; > > > With this the osg::Node description is simply stored as a > osg::Property<osg::Node::DescriptionList> as 'osg.desc' with wrappers to keep > the original > API: > > const DescriptionList& getDescriptions() const { > return getOrCreateProperty<DescriptionList>("osg.desc")->get(); > } > > const std::string& getDescription(unsigned int i) const { > return getOrCreateProperty<DescriptionList>("osg.desc")->get()[i]; > } > > > At the moment there are some missing bits like saving the entire properties > map (not only > userdata/descriptions) and the copyop integration, and also some ugly parts, > for example > the _properties is mutable so that I could keep the existing Descriptions API. > > > I'm eagerly awaiting your thoughts and comments. > Happy New Year everyone and 'Guten Rutsch' (as we say in Germany). > > Cheers, > /ulrich > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
