--
-- File      :  OffsetSurface.cdl
-- Created   :  Sat 9 Jan 1993
-- Author    : CKY / Contract Toubro-Larsen ( TCD )
--
---Copyright : MATRA-DATAVISION  1993
--

class OffsetSurface from IGESGeom  inherits IGESEntity

        ---Purpose: defines IGESOffsetSurface, Type <140> Form <0>
        --          in package IGESGeom
        --          An offset surface is a surface defined in terms of an
        --          already existing surface.If S(u, v) is a parametrised
        --          regular surface and N(u, v) is a differential field of
        --          unit normal vectors defined on the whole surface, and
        --          "d" a fixed non zero real number, then offset surface
        --          to S is a parametrised surface S(u, v) given by
        --          O(u, v) = S(u, v) + d * N(u, v);
        --          u1 <= u <= u2; v1 <= v <= v2;

uses

        Vec from gp,
        XYZ from gp

is

        Create returns mutable OffsetSurface;

        -- Specific Methods pertaining to the class

        Init (me          : mutable;
              anIndicatoR : XYZ;
              aDistance   : Real;
              aSurface    : IGESEntity);
        ---Purpose : This method is used to set the fields of the class
        --           OffsetSurface
        --       - anIndicator : Offset indicator
        --       - aDistance   : Offset distance
        --       - aSurface    : Surface that is offset

        OffsetIndicator (me) returns Vec;
        ---Purpose : returns the offset indicator

        TransformedOffsetIndicator (me) returns Vec;
        ---Purpose : returns the offset indicator after applying Transf. Matrix

        Distance (me) returns Real;
        ---Purpose : returns the distance by which surface is offset

        Surface (me) returns IGESEntity;
        ---Purpose : returns the surface that has been offset

fields

--
-- Class    : IGESGeom_OffsetSurface
--
-- Purpose  : Declaration of variables specific to the definition
--            of the Class OffsetSurface.
--
-- Reminder : A OffsetSurface instance is defined by :
--            The coordinates of offset indicator, the offset distance
--            and the surface to be offset.

        theIndicator : XYZ;
        theDistance  : Real;
        theSurface   : IGESEntity;

end OffsetSurface;