Prototype support clone cells in computational grid generation-line numbering (fortran)

[GolnesaK]

For the prototype / dev version, we treat all obstacles as cutlines. In a later stage, we may either introduce a new layer in the schematisation (clone_cell_cutline) or add a boolean attribute to the obstacle layer (is_clone_cell_cutline).

Implement the following in threedigrid-builder, fortran part:

• number the flowlines (fortran) based on the area mask and the clone nodes

• reorder the 2D lines (old lines might be left out)

  • recognize the new neighbors to the new clone cells

• create flowline (type) between cloned cells (needed info: exchange level, cutline length).

  • the kcu type of this flowline will be a new kcu type