-- File:	Law_Interpolate.cdl
-- Created:	Wed Nov 15 17:30:50 1995
-- Author:	Laurent BOURESCHE
--		<lbo@phylox>
---Copyright:	 Matra Datavision 1995
--- cut and past from GeomAPI_Interpolate in order 
--  to provide 1D interpolation.

class Interpolate from Law

    ---Purpose: This  class   is used  to   interpolate a BsplineCurve
    --          passing through    an  array of  points,   with   a C2
    --          Continuity if tangency  is not requested at the point.
    --          If tangency is  requested at the  point the continuity
    --          will be C1.  If Perodicity is requested the curve will
    --          be  closed  and the junction will  be  the first point
    --          given. The curve will than be only C1
    --          
    --          



uses

    Array1OfReal     from TColStd,
    HArray1OfReal    from TColStd,
    HArray1OfBoolean from TColStd,
    BSpline          from Law

raises
    NotDone           from StdFail,
    ConstructionError from Standard
is
    
    Create(Points       : HArray1OfReal from TColStd;
    	   PeriodicFlag : Boolean       from Standard;
    	   Tolerance    : Real)
    ---Purpose: Tolerance is to check if  the points are not too close
    --          to one an  other.  It is  also  used to check   if the
    --          tangent vector  is not too small.   There should be at
    --          least 2 points. If PeriodicFlag is True then the curve
    --          will be periodic be periodic
    returns Interpolate from Law
    raises ConstructionError from Standard;

    Create(Points       : HArray1OfReal from TColStd;
    	   Parameters   : HArray1OfReal from TColStd;
	   PeriodicFlag : Boolean       from Standard;
    	   Tolerance    : Real          from Standard) 
    ---Purpose: Tolerance is to check if  the points are not too close
    --          to one an  other.  It is  also  used to check   if the
    --          tangent vector  is not too small.   There should be at
    --          least 2 points. If PeriodicFlag is True then the curve
    --          will be periodic be periodic

    --  Warning: There should be as many parameters as there are points
    --          except if  PeriodicFlag is True  then  there should be
    --          one more parameter to close the curve
    returns Interpolate from Law
    raises ConstructionError from Standard;
    
    Load(me : in out;
         InitialTangent : Real from Standard;
	 FinalTangent   : Real from Standard) 
    ---Purpose: loads initial and final tangents if any.
    is static;
    
    Load(me : in out;
         Tangents     : Array1OfReal     from TColStd;
         TangentFlags : HArray1OfBoolean from TColStd)
    ---Purpose: loads the tangents. We should have as many tangents as
    --          they are points  in the array if TangentFlags.Value(i)
    --          is    Standard_True  use the tangent Tangents.Value(i)
    --          otherwise the tangent is not constrained.
    --           
    is static; 
 
    ClearTangents(me : in out);
    ---Purpose: Clears the tangents if any

    Perform(me : in out);
    ---Purpose: Makes the interpolation

    Curve(me) 
    ---C++: return const &
    returns BSpline from Law
    raises NotDone from StdFail
    is static;
	    

    IsDone(me)
    returns Boolean from Standard
    is static;
    
    PerformNonPeriodic(me : in out) 
    ---Purpose: Interpolates in a non periodic fashion.
    is private;
    
    PerformPeriodic(me : in out) 
    ---Purpose: Interpolates in a C1 periodic fashion.
    is private;
	    
fields

    myTolerance      : Real             from Standard;
    -- the 3D tolerance to check for degenerate points
    myPoints         : HArray1OfReal    from TColStd;
    -- the points to interpolates
    myIsDone         : Boolean          from Standard;
    -- the algorithm did complete OK if Standard_True 
    myCurve          : BSpline          from Law;
    -- the interpolated curve
    myTangents       : HArray1OfReal    from TColStd;
    -- the tangents only defined at slot i if 
    -- myTangenFlags->Value(i) is Standard_True 
    myTangentFlags   : HArray1OfBoolean from TColStd;
    -- the flags defining the tangents
    myParameters     : HArray1OfReal    from TColStd;
    -- the parameters used for the cubic interpolation
    myPeriodic       : Boolean          from Standard;
    -- if Standard_True the curve will be periodic
    myTangentRequest : Boolean          from Standard;
    -- Tangents are given if True False otherwise

end Interpolate from Law;