Hello nich29,
I developed the dissipation model cited in the forum message. I read incidentally: "...the case of a more complex shape of breakwater": it seems you are assuming that the presented model is uncapable of deal any other geometry than a quasi 1D domain.
The model is general, the discussion in the cited topic is about the validation on well-defined geometries.
I'm not however going to disclose the complete source code for dealing with complex geometries. Anyway all ingredients are freely available to you in the cited topic.
Michele