[vtkusers] more vtkImagePlaneWidget enhancements

[Dean Inglis]

Hi all,

just can't seem to get enough lately...

middle mouse button does pushing, spinning and rotating.  There are now
visible 'margins' on the slice plane: currently 5% of the in-plane x and y
dimensions.  Picking on the left or right margin rotates the plane around
the local y-prime axis at plane centre.  Similarly, picking on the top or
bottom margin rotates the plane around the local x-prime axis at plane
centre.  Picking one of the four corners of the plane spins the plane around
it's normal.  Picking inside of the margins does a standard push along the
current plane normal.

... AND NOW ...

Holding the shift key and middle mouse picking the plane activates uniform
scaling: mouse move up enlarges the plane while downwards shrinks it.
Holding the control key and middle mouse picking the plane activates plane
edge translation depending on which area of the margins is selected:
1) corners: edges that intersect at a corner are translated
2) edges: edges are translated
3) middle: whole plane is translated

1) and 2) are a really form of constrained 'scaling'.

enjoy...
Dean

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dean Inglis, Ph.D.
Center for Appendicular Magnetic Resonance Studies
25 Charlton Avenue East, Unit 610
Hamilton, ONT, L8N 1Y2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~