-- File:	Geom2dAPI_ExtremaCurveCurve.cdl
-- Created:	Wed Mar 23 15:09:47 1994
-- Author:	Bruno DUMORTIER
--		<dub@fuegox>
---Copyright:	 Matra Datavision 1994


class ExtremaCurveCurve from Geom2dAPI

    	---Purpose: Describes functions for computing all the extrema
    	-- between two 2D curves.
    	-- An ExtremaCurveCurve algorithm minimizes or
    	-- maximizes the distance between a point on the first
    	-- curve and a point on the second curve. Thus, it
    	-- computes the start point and end point of
    	-- perpendiculars common to the two curves (an
    	-- intersection point is not an extremum except where
    	-- the two curves are tangential at this point).
    	-- Solutions consist of pairs of points, and an extremum
    	-- is considered to be a segment joining the two points of a solution.
    	-- An ExtremaCurveCurve object provides a framework for:
    	-- -   defining the construction of the extrema,
    	-- -   implementing the construction algorithm, and
    	-- -   consulting the results.
    	-- Warning
    	-- In some cases, the nearest points between two
    	-- curves do not correspond to one of the computed
    	-- extrema. Instead, they may be given by:
    	-- -   a limit point of one curve and one of the following:
    	--  -   its orthogonal projection on the other curve,
    	--  -   a limit point of the other curve; or
    	-- -   an intersection point between the two curves.
        
uses
    Curve     from Geom2d,
    Curve     from Geom2dAdaptor,
    ExtCC2d   from Extrema,
    Pnt2d     from gp,
    Length    from Quantity,
    Parameter from Quantity
    
raises
    OutOfRange from Standard,
    NotDone    from StdFail
    
    
is

    
    Create(C1   , C2    : Curve from Geom2d;
    	   U1min, U1max : Parameter from Quantity; 
    	   U2min, U2max : Parameter from Quantity)
	---Purpose:  Computes the extrema between
    	-- -   the portion of the curve C1 limited by the two
    	--   points of parameter (U1min,U1max), and
    	-- -   the portion of the curve C2 limited by the two
    	--   points of parameter (U2min,U2max).
    	-- Warning
    	-- Use the function NbExtrema to obtain the number
    	-- of solutions. If this algorithm fails, NbExtrema returns 0.
    returns ExtremaCurveCurve from Geom2dAPI;


--------------------------------------------
-- on ne peut pas utiliser le constructeur vide
-- car n existe pas dans Geom2dExtrema_ExtCC
--------------------------------------------
--    Init(me : in out;
--    	 C1   , C2    : Curve from Geom2d;
--    	 U1min, U1max : Parameter from Quantity; 
--    	 U2min, U2max : Parameter from Quantity)
--    is static;


    NbExtrema(me)
	---Purpose: Returns the number of extrema computed by this algorithm.
    	-- Note: if this algorithm fails, NbExtrema returns 0.
    returns Integer from Standard
	---C++: alias "Standard_EXPORT operator Standard_Integer() const;"
    is static;
    
    
    Points(me; Index  :     Integer from Standard;
    	       P1, P2 : out Pnt2d   from gp )
        ---Purpose: Returns the points P1 on the first curve and P2 on
    	-- the second curve, which are the ends of the
    	-- extremum of index Index computed by this algorithm.
    	-- Exceptions
    	-- Standard_OutOfRange if Index is not in the range [
    	-- 1,NbExtrema ], where NbExtrema is the
    	-- number of extrema computed by this algorithm.
    raises
    	OutOfRange from Standard
	    is static;	       


    Parameters(me; Index  :     Integer   from Standard;
    	     	   U1, U2 : out Parameter from Quantity)
        ---Purpose: Returns the parameters U1 of the point on the first
    	-- curve and U2 of the point on the second curve, which
    	-- are the ends of the extremum of index Index
    	-- computed by this algorithm.
    	-- Exceptions
    	-- Standard_OutOfRange if Index is not in the range [
    	-- 1,NbExtrema ], where NbExtrema is the
    	-- number of extrema computed by this algorithm.
    raises
    	OutOfRange from Standard
	    is static;		    
		    
    
    Distance(me; Index : Integer from Standard)
    returns Length from Quantity
	---Purpose: Computes the distance between the end points of the
    	-- extremum of index Index computed by this algorithm.
    	-- Exceptions
    	-- Standard_OutOfRange if Index is not in the range [
    	-- 1,NbExtrema ], where NbExtrema is the
    	-- number of extrema computed by this algorithm.
    raises
    	OutOfRange from Standard
	    is static;		    
		    
    
    NearestPoints(me; P1, P2 : out Pnt2d from gp)
	---Purpose: Returns the points P1 on the first curve and P2 on
    	-- the second curve, which are the ends of the shortest
    	-- extremum computed by this algorithm.
    	-- Exceptions StdFail_NotDone if this algorithm fails.
    raises
    	NotDone from StdFail
    is static;
    
    
    LowerDistanceParameters(me;  U1, U2 : out Parameter from Quantity)
	---Purpose: Returns the parameters U1 of the point on the first
    	-- curve and U2 of the point on the second curve, which
    	-- are the ends of the shortest extremum computed by this algorithm.
    	-- Exceptions
    	-- StdFail_NotDone if this algorithm fails.
    raises
    	NotDone from StdFail
    is static;
    
    
    LowerDistance(me)
	---Purpose: Computes the distance between the end points of the
    	-- shortest extremum computed by this algorithm.
    	-- Exceptions - StdFail_NotDone if this algorithm fails.
    returns Length from Quantity
	---C++: alias "Standard_EXPORT operator Standard_Real() const;"
    raises
    	NotDone from StdFail
    is static;
    
    
    Extrema(me)
    	---Level: Advanced
	---C++: return const&
	---C++: inline      
    returns ExtCC2d from Extrema
    is static;
    	
	
fields

    myIsDone: Boolean from Standard;
    myIndex : Integer from Standard;    -- index of the nearest solution
    myExtCC : ExtCC2d from Extrema;
    myC1    : Curve   from Geom2dAdaptor;
    myC2    : Curve   from Geom2dAdaptor;

end ExtremaCurveCurve;