bool observer_ptr<>::lock(ref_ptr<T>&) to avoid the temporary ref_ptr<>'s
being created and destroyed on the stack along with the associated ref/unref() operations
Changes:
- new mouse wheel zoom/movement/center functionality
- ability to fix vertical axis (important for CAD)
- possibility to specify values as absolute values or relative to model size
- kind of backward compatibility by flags passed to constructor
- and much more
- restructuring classes to use kind of hierarchy and standard way of event processing (handle methods). This way, there is much more code reusability and it is more easy to develop new kinds of manipulators.
Briefly, the new architecture keeps MatrixManipulator as base abstract class. StandardManipulator is the feature-rich standard manipulator with two main descendant classes: OrbitManipulator and FirstPersonManipulator. OrbitManipulator is base class for all trackball style manipulators, based on center, rotation and distance from center. FirstPersonManipulator is base for walk or fly style manipulators, using position and rotation for camera manipulation.
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Changes by Robert: Replaced osg::Vec3 by osg::Vec3d, introduced DEFAULT_SETTINGS enum and usage. Added frame time member variables in prep for improving throw animation when vysync is off.
which utilises a global recursive mutex that is dedicated to manage Observer and ObserverSet.
The new global mutex for observers avoids problems with deadlocks that were occurring previously when
an osg::Refenced object was being deleted at the same time as on osg::ObserverNodePath.
