INTERFACE SPRange;

IMPORT  SPTriang;

TYPE
  Point = SPTriang.Coords;
  Triangle = ARRAY[0..2] OF Point;
  Function = PROCEDURE (READONLY p: Point): LONGREAL;
 
PROCEDURE OnTriangle(
    READONLY p, q, r: Point;
    func: Function;
    order: CARDINAL
  ): LONGREAL;
  (*
    Computes the maximum absolute function value "ABS(func(p))" 
    over the spherical triangle with corners "p,q,r", using 
    "(order+1)(order+2)/2" sample points. *)

PROCEDURE OnSphere(
    func: Function;
    order: CARDINAL
  ): LONGREAL;
  (*
    Calls OnTriangle for 8 triangles that cover the sphere,
    and returns the MAX of all results. *)

END SPRange.