-- File:	GeomFill_TrihedronLaw.cdl
-- Created:	Tue Dec  2 10:25:37 1997
-- Author:	Philippe MANGIN
--		<pmn@sgi29>
---Copyright:	 Matra Datavision 1997


deferred  class TrihedronLaw from GeomFill inherits TShared from MMgt 

	---Purpose: To define Trihedron along one Curve          
      
uses
 HCurve from  Adaptor3d,    
 PipeError      from GeomFill,   
 Shape  from  GeomAbs, 
 Array1OfReal   from TColStd, 
 Vec    from  gp  
    

raises 
 OutOfRange,  NotImplemented   

is 
 
   SetCurve(me : mutable;  C  :  HCurve  from  Adaptor3d) 
   is  virtual; 
    
   Copy(me)   
   returns  TrihedronLaw  from  GeomFill          
   is  deferred;  
    
   ErrorStatus(me)   
   ---Purpose:Give a status to the Law              
   --         Returns PipeOk (default implementation) 
   returns  PipeError  from  GeomFill 
   is  virtual;   
                 
-- 
--========== To compute Location and derivatives Location
--              
   D0(me : mutable; 
      Param: Real; 
      Tangent    : out  Vec  from  gp; 
      Normal     : out  Vec  from  gp; 
      BiNormal   : out  Vec  from  gp)
      ---Purpose: compute Triedrhon on curve at parameter <Param>         
   returns Boolean  is  deferred;
	
   D1(me : mutable;
      Param: Real;       
      Tangent    : out  Vec  from  gp;  
      DTangent   : out  Vec  from  gp; 
      Normal     : out  Vec  from  gp; 
      DNormal    : out  Vec  from  gp;                 
      BiNormal   : out  Vec  from  gp; 
      DBiNormal  : out  Vec  from  gp)
      ---Purpose: compute Triedrhon and  derivative Trihedron  on curve
      --          at parameter <Param>                
      --  Warning : It used only for C1 or C2 aproximation
   returns Boolean  
   raises  NotImplemented 
   is  virtual; 
   
   D2(me : mutable;
      Param: Real;       
      Tangent    : out  Vec  from  gp;  
      DTangent   : out  Vec  from  gp; 
      D2Tangent  : out  Vec  from  gp; 
      Normal     : out  Vec  from  gp; 
      DNormal    : out  Vec  from  gp;                 
      D2Normal   : out  Vec  from  gp; 
      BiNormal   : out  Vec  from  gp; 
      DBiNormal  : out  Vec  from  gp; 
      D2BiNormal : out  Vec  from  gp)    
      ---Purpose: compute  Trihedron on curve          
      --          first and seconde  derivatives.
      --  Warning : It used only for C2 aproximation
   returns Boolean
   raises  NotImplemented  
   is  virtual; 
--
--  =================== Management  of  continuity  ===================
--                 
   NbIntervals(me; S : Shape from GeomAbs) 
	---Purpose: Returns  the number  of  intervals for  continuity
	--          <S>. 
        --          May be one if Continuity(me) >= <S>
   returns Integer  is  deferred;

   Intervals(me; T : in out Array1OfReal from TColStd; 
    	         S : Shape from GeomAbs)
	---Purpose: Stores in <T> the  parameters bounding the intervals
	--          of continuity <S>.
	--          
	--          The array must provide  enough room to  accomodate
	--          for the parameters. i.e. T.Length() > NbIntervals()
    raises
    	OutOfRange from Standard 
    is deferred;  
     
    	
   SetInterval(me: mutable; First, Last: Real from Standard)    
	---Purpose: Sets the bounds of the parametric interval on 
	--          the function
	--          This determines the derivatives in these values if the
	--          function is not Cn.
   is virtual; 
   
    GetInterval(me: mutable; First, Last: out  Real from Standard)    
	---Purpose: Gets the bounds of the parametric interval on 
	--          the function
    is static; 
	  
--  ===================  To help   computation of  Tolerance   ===============	 
    GetAverageLaw(me  :  mutable;
      ATangent    : out  Vec  from  gp; 
      ANormal     : out  Vec  from  gp; 
      ABiNormal   : out  Vec  from  gp) 
     ---Purpose: Get average value of M(t) and V(t) it is usfull to 
     --          make fast approximation of rational  surfaces.        
  is  deferred;

--   =================== To help Particular case   ===============	
   
    IsConstant(me) 
    ---Purpose: Say if the law is Constant

    --          Return False by Default.        
    returns  Boolean   
    is virtual;  
     
     
    IsOnlyBy3dCurve(me) 
     ---Purpose: Say if the law is defined, only by the 3d Geometry of
     --          the setted Curve  
     --          Return False by Default.        
    returns  Boolean   
    is virtual;           
     
    
fields 
    myCurve  :  HCurve  from  Adaptor3d  is  protected;--  The curve  definition 
    myTrimmed:  HCurve  from  Adaptor3d  is  protected;--  The  curve  to  used
end TrihedronLaw;