[vtk-developers] Tweaking vtkCoordinate

[John Biddiscombe]

I'd like to add a new option to vtkCoordinate
VTK_USERDEFINED
and add a new option for conversion.

* * The new method will be virtual * *

The existing methods are not virtual and the user will be required to 
subclass vtkCoordinate and supply a transformation in the method
float *GetComputedUserDefinedValue
which would be called from inside
GetComputedFloatDisplayValue

The reason for adding this would be to enable the user of 
vtkPolyDataMapper2D to supply a TransformCoordinate with a custom mapping 
set. This will enable us (me?) to render 2D over 3D and use a separate 
coordinate system for 3D and 2D.

I don't believe this will affect anything much apart from an additional 
case statement in the above mentioned code. If anyone would like to suggest 
an alternative way of achieving this....please do.

I'd welcome objections/approval before I proceed.

JB