-- File:	FairCurve_Energy.cdl<2>
-- Created:	Wed Mar  6 10:09:03 1996
-- Author:	Philippe MANGIN
--		<pmn@sgi29>
---Copyright:	 Matra Datavision 1996


deferred class Energy from FairCurve 
    inherits MultipleVarFunctionWithHessian from math

	---Purpose: necessary methodes to compute the energy of an FairCurve.
	---Category: Advanced use

uses Vector  from  math,
     Matrix  from math,
     HArray1OfPnt2d from TColgp,
     Array1OfXY  from TColgp,
     Pnt2d from gp,
     HArray1OfReal from TColStd


is   
     Initialize(Poles         : HArray1OfPnt2d;
    	    	ConstrOrder1  : Integer;
	   	ConstrOrder2  : Integer;
	        WithAuxValue  : Boolean = Standard_False;
            	Angle1        : Real = 0;
            	Angle2        : Real = 0;
		Degree        : Integer = 2;
                Curvature1    : Real = 0;
    	        Curvature2    : Real = 0);
	---Purpose: Angles corresspond to the Ox axis
	--          ConstrOrder1(2) can be equal to 0, 1 or 2
  
    NbVariables(me)
    	---Purpose: returns the number of variables of the energy.

    returns Integer is redefined;
    ---C++: inline


    Value(me: in out; X: Vector; E: out Real)
    	---Purpose: computes the values of the Energys E for the 
    	--          variable <X>.
    	--          Returns True if the computation was done successfully, 
    	--          False otherwise.

    returns Boolean
    is redefined;
    
    
    Gradient(me: in out; X: Vector; G: out Vector)
    	---Purpose:computes the gradient <G> of the energys for the 
    	--         variable <X>.
    	--         Returns True if the computation was done successfully, 
    	--         False otherwise.

    returns Boolean
    is redefined;
    
    Gradient1(me : in out; TheVector: Vector; G: out Vector)
    	---Purpose: It is use internaly to make the Gradient Vector <G> 
    is protected;


    Values(me: in out; X: Vector; E: out Real; G: out Vector)
    	---Purpose: computes the Energy <E> and the gradient <G> of the 
    	--          energy for the variable <X>.
    	--          Returns True if the computation was done successfully, 
    	--          False otherwise.

    returns Boolean
    is redefined;    
    
    Values(me: in out; X: Vector; E: out Real; G: out Vector; H: out Matrix)
    	---Purpose: computes the Energy  <E>, the gradient <G> and the
    	--          Hessian   <H> of  the  energy  for  the   variable <X>.
    	--          Returns   True  if    the  computation   was  done
    	--          successfully, False otherwise.

    returns Boolean
    is redefined;
    
    Variable(me; X: out Vector)
    ---Purpose: compute the variables <X> wich correspond with the field <MyPoles>
    returns Boolean
    is virtual;
    
    Hessian1(me : in out; TheVector : Vector; H: out Matrix)
    ---Purpose: It is use internaly to make the Hessian Matrix <H> 
    is protected; 
    
    Poles(me)
    ---Purpose: return  the  poles
    ---C++: inline
    ---C++: return const&
    returns  HArray1OfPnt2d;
 
    ComputePoles(me: in out; X: Vector)
    ---Purpose: compute  the  poles wich correspond with the variable X
    is virtual protected;
    
    Indice(me; i,j : Integer)
    ---C++: inline
    returns Integer
    is protected;
    
    ComputePolesG1(me; Side : Integer; Lambda : Real; P1: Pnt2d; P2 : in out Pnt2d) 
    ---Purpose: compute  the  pole wich depend of variables and G1 constraint   
    is  protected;
    
    ComputePolesG2(me; Side : Integer; Lambda, Rho : Real; P1: Pnt2d; P2 : in out Pnt2d) 
    ---Purpose: compute  the  pole wich depend of variables and G2 constraint   
    is  protected;
     
    Compute(me:in out; DerivativeOrder : Integer; Result : out Vector)
        ---Purpose: compute the energy (and derivatives) in intermediat format
    returns Boolean 
    is deferred protected;
    
fields
    MyPoles         : HArray1OfPnt2d is protected;
    MyContrOrder1   : Integer        is protected;
    MyContrOrder2   : Integer        is protected;
    MyWithAuxValue  : Boolean        is protected;
    MyNbVar         : Integer        is protected;
    MyNbValues      : Integer  ;      
    MyLinearForm    : Array1OfXY;
    MyQuadForm      : Array1OfXY;    
    MyGradient      : Vector    ;  
    MyHessian       : Vector    ;   
end Energy;