Simone Giannecchini ha scritto:
> I have a few doubts about the update of ReferencedEnvelope. Are you
> sure it is already capable of doing 3D semantic-wise?
> It implementes BoundingBox which is purely 2D and that's why it is
> used almost everywhere in the feature code. If we start to put 3d
> envelopes in it, we would be clearly violating the BoundingBox
> interface or, put it another way, what is going to be the meaning of x
> and y with a 3D crs ( it might seem a naive question and probably is,
> but I am trying to understand which assumptions we are making).

ReferencedEnvelope extends jts envelope and implements
org.opengis.geometry.Envelope and BoundingBox

JTS Envelope and BoundingBox are 2 dimensional,
org.opengis.geometry.Envelope is n-dimensional and we implement
the getDimension() and getMimumum(ordinate)/getMaximum(ordinate)
that do allow to grab dimensions above the second.

I was thinking that extending the class to n dimensions produces
no harm, whoever is using it as a 2d one just won't notice the
extra dimensions.

I'm still doubtful about methods that do check relationships
between envelopes thought. What should we do when a nd and
a 2d envelope are compared? Flatten the nd one or return a
marker that the comparison does not make sense.

The main reason to have a 3d envelope class is to be able
and return the 3d envelope of 3d data sets as well.
As an alternative I guess I could sublcass ReferencedEnvelope,
but that would create even more confusion...

Thoughts?
Cheers
Andrea

-- 
Andrea Aime
OpenGeo - http://opengeo.org
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