-- File:	GCPnts_QuasiUniformAbscissa.cdl
-- Created:	Thu Aug 22 15:49:19 1996
-- Author:	Stagiaire Mary FABIEN
--		<fbi@zozox.paris1.matra-dtv.fr>
---Copyright:	 Matra Datavision 1996

class QuasiUniformAbscissa from GCPnts 


    ---Purpose: This class provides an algorithm to compute a uniform abscissa
    -- distribution of points on a curve, i.e. a sequence of
    -- equidistant points. The distance between two
    -- consecutive points is measured along the curve.
    -- The distribution is defined:
    -- -   either by the curvilinear distance between two consecutive points
    -- -   or by a number of points.
uses 
    Curve        from Adaptor3d,
    Curve2d      from Adaptor2d,
    HArray1OfReal from TColStd

    
raises DomainError       from Standard, 
       ConstructionError from Standard,
       OutOfRange        from Standard,
       NotDone           from StdFail

is
        
    Create 
    	---Purpose: Constructs an empty algorithm. To define the problem
        -- to be solved, use the function Initialize.
    	returns QuasiUniformAbscissa from GCPnts;

    Create(C : in out Curve from Adaptor3d ; NbPoints : Integer)
        --- Purpose : Computes a uniform abscissa distribution of points
        -- -   on the curve C where Abscissa is the curvilinear distance between
	-- two consecutive points of the distribution.
    	returns QuasiUniformAbscissa from GCPnts
     	raises ConstructionError,
               DomainError;

    Create(C : in out Curve from Adaptor3d ; NbPoints : Integer; U1, U2 : Real)
        --- Purpose : Computes a uniform abscissa distribution of points
	--   on the part of curve C limited by the two parameter values U1 and U2,
	--     where Abscissa is the curvilinear distance between
	-- two consecutive points of the distribution.
	-- The first point of the distribution is either the origin of
	-- curve C or the point of parameter U1. The following
	-- points are computed such that the curvilinear
	-- distance between two consecutive points is equal to Abscissa.
	-- The last point of the distribution is either the end
	-- point of curve C or the point of parameter U2.
	-- However the curvilinear distance between this last
	-- point and the point just preceding it in the distribution
	-- is, of course, generally not equal to Abscissa.
	-- Use the function IsDone to verify that the
	-- computation was successful, the function NbPoints
	-- to obtain the number of points of the computed
	-- distribution, and the function Parameter to read the
	-- parameter of each point.
	-- Warning
	-- The roles of U1 and U2 are inverted if U1 > U2 .
	-- Warning
	-- C is an adapted curve, that is, an object which is an
	-- interface between:
	-- -   the services provided by either a 2D curve from
	--   the package Geom2d (in the case of an
	--   Adaptor2d_Curve2d curve) or a 3D curve from
	--   the package Geom (in the case of an Adaptor3d_Curve curve),
	-- -   and those required on the curve by the computation algorithm.
        returns QuasiUniformAbscissa from GCPnts
     	raises ConstructionError,
               DomainError;

  
    Initialize(me : in out; C : in out Curve from Adaptor3d ; NbPoints : Integer)
    	---Purpose: Initialize the algoritms with <C>, <NbPoints> and 
     	raises ConstructionError
	is static;


    Initialize(me : in out; C : in out Curve from Adaptor3d ; NbPoints : Integer; U1, U2 : Real)
    	---Purpose: Initialize the algoritms with <C>, <Abscissa>, <U1>,
    	--          <U2>.
     	raises ConstructionError,
               DomainError
	is static;

    Create(C : in out Curve2d from Adaptor2d ; NbPoints : Integer)
        --- Purpose : Computes a uniform abscissa distribution of points on 
        --  the Curve2d <C>. 
        --  <NbPoints> defines the nomber of desired points. 
    	returns QuasiUniformAbscissa from GCPnts
     	raises ConstructionError,
               DomainError;

    Create(C : in out Curve2d from Adaptor2d ; NbPoints : Integer; U1, U2 : Real)
        --- Purpose : Computes a Uniform abscissa distribution of points 
        --  on a part of the Curve2d <C>. 
     	returns QuasiUniformAbscissa from GCPnts
     	raises ConstructionError,
               DomainError;

    Initialize(me : in out; C : in out Curve2d from Adaptor2d ; NbPoints : Integer)
    	---Purpose: Initialize the algoritms with <C>, <NbPoints> and 
     	raises ConstructionError
	is static;


    Initialize(me : in out; C : in out Curve2d from Adaptor2d ; NbPoints : Integer; U1, U2 : Real)
    	---Purpose: Initialize the algoritms with <C>, <Abscissa>, <U1>,
    	--          <U2>.
     	raises ConstructionError,
               DomainError
	is static;

	       
    IsDone(me) returns Boolean 
	---C++: inline
	---Purpose: Returns true if the computation was successful.
	-- IsDone is a protection against:
	-- -   non-convergence of the algorithm
	-- -   querying the results before computation.
    	is static;

	       
    NbPoints(me) returns Integer
	---C++: inline
	---Purpose:
	-- Returns the number of points of the distribution
	-- computed by this algorithm.
	-- This value is either:
	-- -   the one imposed on the algorithm at the time of
	--   construction (or initialization), or
	-- -   the one computed by the algorithm when the
	--   curvilinear distance between two consecutive
	--   points of the distribution is imposed on the
	--   algorithm at the time of construction (or initialization).
	--   Exceptions
	-- StdFail_NotDone if this algorithm has not been
	-- initialized, or if the computation was not successful.
    	 is static;
  
    Parameter(me; Index : Integer) returns Real 
	---C++: inline
        ---Purpose : Returns the parameter of the point of index Index in
	-- the distribution computed by this algorithm.
	-- Warning
	-- Index must be greater than or equal to 1, and less
	-- than or equal to the number of points of the
	-- distribution. However, pay particular attention as this
	-- condition is not checked by this function.
	-- Exceptions
	-- StdFail_NotDone if this algorithm has not been
	-- initialized, or if the computation was not successful.
    	is static;
   
fields

    myDone       : Boolean;
    myNbPoints   : Integer ;
    -- stores the number of points computed with the 
    -- requested Abscissa else stores the requested
    -- number of points 
    myAbscissa   : Real;
    myParams     : HArray1OfReal from TColStd ;
    -- the size of this array will be be bigger than myNbPoints
    --  by one or two 

end QuasiUniformAbscissa;