Cell function

As explained earlier, at least two coordinates systems exist in Bcube : the "reference" coordinates (ReferenceDomain) and the "physical" coordinates (PhysicalDomain). The evaluation of a function on a point in a cell depends on the way this point has been defined. Hence the definition of CellPoints that embed the coordinate system. Given a CellPoint (or eventually a FacePoint), an AbstractCellFunction will be evaluated and the mapping between the ReferenceDomain to the PhysicalDomain (or reciprocally) will be performed internally if necessary : if an AbstractCellFunction defined in terms of reference coordinates is applied on a CellPoint expressed in the reference coordinates system, no mapping is needed.