[vtkusers] strange behaviour (bug?) vtkTextActor y-positioning and sizing (ScaledText)

[Charl Botha]

Dear all,

I've created a short Python example and two screenshots to illustrate
the problem: http://visualisation.tudelft.nl/~cpbotha/thingies/vtktextactor_ybug/

Unless I'm doing something wrong, vtkTextActor is showing some very
strange behaviour in ScaledText mode with regard to its
Position2Coordinate.  In short, documentation seems to claim that the
Position2Coordinate is relative to PositionCoordinate.  However, the
x-component does work as expected (p2c relative to pc), whereas the y
partly does when y < 0 and doesn't at all when y > 0.  The Python
examples contains more details documentation on how and when exactly
it goes wrong.

I tested this with a ParaView-3-2-1 checkout of VTK.  As far as I can
see, no changes have been made to vtkTextActor* since then in VTK CVS
head.

If anyone could shed some light on this, I'd be most grateful.

Thanks,
Charl