Implicit Widget Representations Improvements

VTK has better support for several vtkWidgetRepresentation subclasses.

Bug fixes

Interactions are smoother thanks to a better Picker choice. Also, interactively modifying radius (for Annulus, Cone and Cylinder) used to be based on screen motion. Switching to mouse world position makes it more intuitive: circle effectively follow the mouse cursor.

New BoundedWidget design

vtkBoundedWidgetRepresentation is a new vtkWidgetRepresentation subclass, to inherits from to benefit of a “crop at outline” feature. This is useful for most vtkImplicitFunction representations.

API breaking changes

The classes that were ported to the vtkBoundedWidgetRepresentation design loose some protected member, as the new parent class has same member as private. Please use the Getters instead.

Concerned classes: vtkImplicitConeRepresentation, vtkImplicitCylinderRepresentation, vtkImplicitAnnulusRepresentation and vtkImplicitPlaneRepresentation