-- File:	Circ2dTanCen.cdl
-- Created:	Thu Mar 28 17:10:45 1991
-- Author:	Remi GILET
--		<reg@topsn2>
---Copyright:	 Matra Datavision 1991

generic class Circ2dTanCen from GccGeo
    (TheCurve          as any; -- 
     TheCurveTool      as any; -- as CurveTool(TheCurve) from GccInt
     TheExtPC          as any; -- as ExtPC(TheCurve,TheCurveTool) from Extrema
     TheQualifiedCurve as any) -- as QCurve from GccInt
       	    	    	       --          (TheCurve)

	---Purpose: This class implements the algorithms used to 
	--          create 2d circles tangent to a curve and 
	--          centered on a point. 
	--          The arguments of all construction methods are :
	--             - The qualified element for the tangency constrains 
	--             (QualifiedCurv).
	--             -The center point Pcenter.
	--             - A real Tolerance.
	--          Tolerance is only used in the limits cases.
    	--          For example : 
    	--          We want to create a circle tangent to an EnclosedCurv C1
    	--          with a tolerance Tolerance.
    	--          If we did not use Tolerance it is impossible to 
    	--          find a solution in the following case : Pcenter is
    	--          outside C1.
    	--          With Tolerance we will give a solution if the distance
    	--          between C1 and Pcenter is lower than or equal Tolerance/2.

-- inherits Entity from Standard

uses Pnt2d            from gp,
     Circ2d           from gp,
     Array1OfCirc2d   from TColgp,
     Array1OfPnt2d    from TColgp,
     Array1OfReal     from TColStd,
     Array1OfInteger  from TColStd,
     Position         from GccEnt,
     Array1OfPosition from GccEnt

raises OutOfRange   from Standard,
       BadQualifier from GccEnt,
       NotDone      from StdFail

is

Create( Qualified1 : TheQualifiedCurve              ;
        Pcenter    : Pnt2d             from gp      ;
        Tolerance  : Real              from Standard) returns Circ2dTanCen
    ---Purpose: This method implements the algorithms used to 
    --          create 2d circles tangent to a circle and 
    --          centered on a point. 
raises BadQualifier;

-- -- ....................................................................

IsDone(me) returns Boolean from Standard
is static;
    ---Purpose: This method returns True if the construction 
    --          algorithm succeeded.

NbSolutions(me) returns Integer from Standard
    	---Purpose: Returns the number of solutions and raises NotDone 
    	--          exception if the algorithm didn't succeed.
raises NotDone
is static;
        ---Purpose: It raises NotDone if the construction algorithm 
        --          didn't succeed.

ThisSolution(me                           ;
    	     Index : Integer from Standard) returns Circ2d from gp
    ---Purpose: Returns the solution number Index and raises OutOfRange 
    --          exception if Index is greater than the number of solutions.
    --          Be carefull: the Index is only a way to get all the 
    --          solutions, but is not associated to theses outside the 
    --          context of the algorithm-object.
raises OutOfRange, NotDone
is static;
    ---Purpose: It raises NotDone if the construction algorithm 
    --          didn't succeed.
    --          It raises OutOfRange if Index is greater than the 
    --          number of solutions or less than zero.

WhichQualifier(me                                  ;
    	       Index   :     Integer  from Standard;
	       Qualif1 : out Position from GccEnt  )
raises OutOfRange, NotDone
is static;
    -- It returns the informations about the qualifiers of the tangency 
    -- arguments concerning the solution number Index.
    -- It returns the real qualifiers (the qualifiers given to the 
    -- constructor method in case of enclosed, enclosing and outside 
    -- and the qualifiers computedin case of unqualified).

Tangency1(me                                     ;
          Index         : Integer   from Standard;
          ParSol,ParArg : out Real  from Standard;
          PntSol        : out Pnt2d from gp      )
    ---Purpose: Returns informations about the tangency point between the 
    --          result number Index and the first argument.
    --          ParSol is the intrinsic parameter of the point PntSol 
    --          on the solution curv.
    --          ParArg is the intrinsic parameter of the point PntArg 
    --          on the argument curv.
raises OutOfRange, NotDone
is static;
    ---Purpose: It raises NotDone if the construction algorithm 
    --          didn't succeed.
    --          It raises OutOfRange if Index is greater than the 
    --          number of solutions or less than zero.

fields

    WellDone : Boolean from Standard;
    -- True if the algorithm succeeded.

    NbrSol   : Integer from Standard;
    -- The number of possible solutions. We have to decide about the
    -- status of the multiple solutions...

    cirsol   : Array1OfCirc2d from TColgp;
    ---Purpose : The solutions.

    qualifier1 : Array1OfPosition from GccEnt;
    -- The qualifiers of the first argument.

    pnttg1sol   : Array1OfPnt2d from TColgp;
    -- The tangency point between the solution and the first argument on 
    -- the solution.

    par1sol   : Array1OfReal from TColStd;
    -- The parameter of the tangency point between the solution and the 
    -- first argument on the solution.

    pararg1   : Array1OfReal from TColStd;
    -- The parameter of the tangency point between the solution and the first 
    -- argument on the first argument.

end Circ2dTanCen;