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

class OffsetCurve from IGESGeom  inherits IGESEntity

        ---Purpose: defines IGESOffsetCurve, Type <130> Form <0>
        --          in package IGESGeom
        --          An OffsetCurve entity contains the data necessary to
        --          determine the offset of a given curve C. This entity
        --          points to the base curve to be offset and contains
        --          offset distance and other pertinent information.

uses

        Vec         from gp,
        XYZ         from gp

is

        Create returns mutable OffsetCurve;

        -- Specific Methods pertaining to the class

        Init (me                 : mutable;
              aBaseCurve         : IGESEntity;
              anOffsetType       : Integer;
              aFunction          : IGESEntity;
              aFunctionCoord     : Integer;
              aTaperedOffsetType : Integer;
              offDistance1       : Real;
              arcLength1         : Real;
              offDistance2       : Real;
              arcLength2         : Real;
              aNormalVec         : XYZ;
              anOffsetParam      : Real;
              anotherOffsetParam : Real);
        ---Purpose : This method is used to set the fields of the class
        --           OffsetCurve
        --       - aBaseCurve         : The curve entity to be offset
        --       - anOffsetType       : Offset distance flag
        --                              1 = Single value, uniform distance
        --                              2 = Varying linearly
        --                              3 = As a specified function
        --       - aFunction          : Curve entity, one coordinate of which
        --                              describes offset as a function of its
        --                              parameter (0 unless OffsetType = 3)
        --       - aFunctionCoord     : Particular coordinate of curve
        --                              describing offset as function of its
        --                              parameters. (used if OffsetType = 3)
        --       - aTaperedOffsetType : Tapered offset type flag
        --                              1 = Function of arc length
        --                              2 = Function of parameter
        --                              (Only used if OffsetType = 2 or 3)
        --       - offDistance1       : First offset distance
        --                              (Only used if OffsetType = 1 or 2)
        --       - arcLength1         : Arc length or parameter value of
        --                              first offset distance
        --                              (Only used if OffsetType = 2)
        --       - offDistance2       : Second offset distance
        --       - arcLength2         : Arc length or parameter value of
        --                              second offset distance
        --                              (Only used if OffsetType = 2)
        --       - aNormalVec         : Unit vector normal to plane containing
        --                              curve to be offset
        --       - anOffsetParam      : Start parameter value of offset curve
        --       - anotherOffsetParam : End parameter value of offset curve

        BaseCurve (me) returns IGESEntity;
        ---Purpose : returns the curve to be offset

        OffsetType (me) returns Integer;
        ---Purpose : returns the offset distance flag
        -- 1 = Single value offset (uniform distance)
        -- 2 = Offset distance varying linearly
        -- 3 = Offset distance specified as a function

        Function (me) returns IGESEntity;
        ---Purpose : returns the function defining the offset if at all the offset
        -- is described as a function or Null Handle.

        HasFunction (me) returns Boolean;
        ---Purpose : returns True if function defining the offset is present.

        FunctionParameter (me) returns Integer;
        ---Purpose : returns particular coordinate of the curve which describes offset
        -- as a function of its parameters. (only used if OffsetType() = 3)

        TaperedOffsetType (me) returns Integer;
        ---Purpose : returns tapered offset type flag (only used if OffsetType() = 2 or 3)
        -- 1 = Function of arc length
        -- 2 = Function of parameter

        FirstOffsetDistance (me) returns Real;
        ---Purpose : returns first offset distance (only used if OffsetType() = 1 or 2)

        ArcLength1 (me) returns Real;
        ---Purpose : returns arc length or parameter value (depending on value of
        -- offset distance flag) of first offset distance
        -- (only used if OffsetType() = 2)

        SecondOffsetDistance (me) returns Real;
        ---Purpose : returns the second offset distance

        ArcLength2 (me) returns Real;
        ---Purpose : returns arc length or parameter value (depending on value of
        -- offset distance flag) of second offset distance
        -- (only used if OffsetType() = 2)

        NormalVector (me) returns Vec;
        ---Purpose : returns unit vector normal to plane containing curve to be offset

        TransformedNormalVector (me) returns Vec;
        ---Purpose : returns unit vector normal to plane containing curve to be offset
        -- after applying Transf. Matrix

        Parameters (me; StartParam, EndParam : out Real);
        -- returns start and end parameter values of the offset curve

    	StartParameter (me) returns Real;
	---Purpose : returns Start Parameter value of the offset curve

    	EndParameter (me)   returns Real;
	---Purpose : returns End   Parameter value of the offset curve

fields

--
-- Class    : IGESGeom_OffsetCurve
--
-- Purpose  : Declaration of variables specific to the definition
--            of the Class OffsetCurve.
--
-- Reminder : A OffsetCurve instance is defined by :
--            The curve to be offset, the offset type (indicating
--            whether the offset is single valued, or varies linearly
--            or is a function), the curve representing the function
--            in case offset is specified as a function, the offset
--            distances, unit vector normal to the plane containing
--            offset curve, the starting and ending parameters of offset
--            curve

        theBaseCurve         : IGESEntity;
        theOffsetType        : Integer;
        theFunction          : IGESEntity;
        theFunctionCoord     : Integer;
        theTaperedOffsetType : Integer;
        theOffsetDistance1   : Real;
        theArcLength1        : Real;
        theOffsetDistance2   : Real;
        theArcLength2        : Real;
        theNormalVector      : XYZ;
        theOffsetParam1      : Real;
        theOffsetParam2      : Real;

end OffsetCurve;