INTERFACE AttributesIso2D;

IMPORT Neighborhood2D;

CONST N = 5;
  (* 
    Number of local attributes per texel *)
  
TYPE T = ARRAY [0..N-1] OF REAL; 
  (* 
    A set of local attributes *)
  
VAR Name: TEXT;
  
PROCEDURE FromNeighborhood(READONLY z: Neighborhood2D.T; VAR (*OUT*) a: T);
  (*
    Computes the attribute set from a texel neighborhood. *)
 
PROCEDURE EnergyAndStateForcesFromStateNeigborhood(
    READONLY z: ARRAY OF Neighborhood2D.T;       (* Multi-layer neighborhood *)
    energy: LocalEvaluator.T;                    (* Local energy evaluator *)
    VAR (*OUT*) E: LONGREAL;                     (* Computed local energy *)
    VAR (*OUT*) dEdz: ARRAY OF Neighborhood2D.T; (* Derivatives of "E" rel.to "z" *)
  );
  (*
    Computes the energy term associated with one texel, and
    its partial derivatives relative to the texel values, 
    from the texel's neighborhood. *)

END Attributes2D.