Statistics

Statistics contains general facilities for recording and collecting statistical data like counts and times. It is mainly used for collecting rendering statistics like the amount of time need for a frame or the number of visible polygons, but it can be used for any kind of statistics.

The statistics data is collected in the form of single osg::StatElem structures which are bundled in a osg::StatCollector. Every StatElem element can have one of a number of different types, the predefined ones are Int (osg::StatIntElem), Real32 (osg::StatRealElem), Time (osg::StatTimeElem) and String (osg::StatStringElem). Every StatElement also has a description in the form of a StatElemDesc that describes the actual use of the element. The StatCollector can hold an arbitrary subset of all known elements. The StatElemDesc obj holding the element type and ID must exist as long as any collector holds a corresponding elem object. The StatElemDesc constructor creates a unique ID which can be used to create/access an correspondent Elem (which holds the value) in any collector.

The contents of the StatCollector can be accessed either for every StatElem separately or can be output as a whole in the form of a string. For displaying the contents of a StatCollector on screen the osg::SimpleStatisticsForground and osg::GraphicStatisticsForeground can be used. The various StatElem objects provide methods to access or change the value (e.g get/set increase/decrease) In addition, every StatElem holds a on-flag to activate/deactivate the statistic element.

The main idea of the Statistics structure lies in high flexibility. Thus the set of variables that are statistically relevant is not fixed, new ones can be added by the application if necessary.

Stat Elem/Desc/Collector relation

Dev: To extend the Statistics you just need to create an instance of the osg::StatElemDesc class. It is templated and parametrized by the osg::StatElem that the new variable should have.

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