Harmonized dimension estimation in OracleGeometryWriter

[hlaebe]

There was an inconsistency in getting the correct dimension from th e geomtry to be transformed to SdoGeometry. One was based on the Coordinate property and one on the coordinatesequence dimension. It seems that internally all coordinates are 3D now, even for 2D (Z is NaN then). This lead to incorrect SdoGeometry having ElemInfo telling 2D and an ordinate array containing 3 ordinates (including NaN).

The pull request fixes this by defining the dimension prior to conversion based on coordinate property and storing it in private variable in the Writer instance.

fixes #11

[hlaebe]

@airbreather @FObermaier Any reasons why this PR doesn't make it to production ? BR, Holger

[FObermaier]

You are right that the computation of the geometry dimension is not consistent.
A better fix would be to compute the dimension based on CoordinateSequence, too.

Sth along these lines:

private class SpatialDimensionDeterminator : IEntireCoordinateSequenceFilter {
    public void Filter(CoordinateSequence sequence) {
        NumSpatialDimensions = sequence.Dimension - sequence.Measures;
        Done = true;
    }
    public int NumSpatialDimensions { get; private set; } = 2;
    public bool Done { get; private set; }
    public bool GeometryChanged => false;
}

private static int Dimension(Geometry geom) {
    var sdd = new SpatialDimensionDeterminator();
    geom.Apply(sdd);
    return sdd.NumSpatialDimensions
}

[FObermaier]

I don't like this as it messes things up in a re-entrant scenario. Make dimension a local variable and pass it to the private specific Write functions.