OCCT/src/LProp/LProp_CLProps.cdl

-- Created on: 1991-03-25
-- Created by: Michel CHAUVAT
-- Copyright (c) 1991-1999 Matra Datavision
-- Copyright (c) 1999-2012 OPEN CASCADE SAS
--
-- The content of this file is subject to the Open CASCADE Technology Public
-- License Version 6.5 (the "License"). You may not use the content of this file
-- except in compliance with the License. Please obtain a copy of the License
-- at http://www.opencascade.org and read it completely before using this file.
--
-- The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
-- main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
--
-- The Original Code and all software distributed under the License is
-- distributed on an "AS IS" basis, without warranty of any kind, and the
-- Initial Developer hereby disclaims all such warranties, including without
-- limitation, any warranties of merchantability, fitness for a particular
-- purpose or non-infringement. Please see the License for the specific terms
-- and conditions governing the rights and limitations under the License.



generic class CLProps from LProp
                         (Curve as any;
                    	  Vec   as any; -- as Vec or Vec2d
		     	  Pnt   as any; -- as Pnt or Pnt2d
		   	  Dir   as any; -- as Dir or Dir2d
                   	  Tool  as any) -- as ToolCurve(Curve, Pnt, Vec)  

    ---Purpose: Computation of Curve Local Properties:
    --          - point,
    --          - derivatives,
    --          - tangent,
    --          - normal plane,
    --          - curvature,
    --          - normal,
    --          - centre of curvature,

uses    Status from LProp

raises  BadContinuity from LProp, 
        DomainError   from Standard, 
        OutOfRange    from Standard, 
        NotDefined    from LProp
is


    Create(C: Curve; N: Integer; Resolution: Real)
    	---Purpose: Initializes the local properties of the curve <C> 
    	--          The current point and the derivatives are 
    	--          computed at the same time, which allows an 
    	--          optimization of the computation time.
    	--          <N> indicates the maximum number of derivations to 
    	--          be done (0, 1, 2 or 3). For example, to compute 
    	--          only the tangent, N should be equal to 1.
    	--          <Resolution> is the linear tolerance (it is used to test
    	--          if a vector is null).
    	returns CLProps
    	raises OutOfRange;
	    	-- if N < 0 or N > 3.

    Create(C: Curve; U : Real; N: Integer; Resolution: Real)
        --- Purpose : Same as previous constructor but here the parameter is
        --            set to the value <U>.
        --            All the computations done will be related to <C> and <U>.
    	returns CLProps
    	raises OutOfRange;
	    	-- if N < 0 or N > 3.
	    	
    Create(N : Integer;Resolution:Real)
        --- Purpose : Same as previous constructor but here the parameter is
        --            set to the value <U> and the curve is set 
        --            with SetCurve.
        --            the curve can have a empty constructor
        --            All the computations done will be related to <C> and <U>
        --            when the functions "set" will be done.

    returns CLProps
    raises OutOfRange;
    
    SetParameter(me: in out; U : Real)
    	---Purpose: Initializes the local properties of the curve 
    	--          for the parameter value <U>.
	is static;
	    	
    SetCurve(me: in out; C : Curve)
    	---Purpose: Initializes the local properties of the curve 
    	--          for the new curve.
	is static;

    Value(me) returns Pnt is static;
    	---Purpose: Returns the Point.
    	---C++: return const &

    D1(me: in out) returns Vec is static;
    	---Purpose: Returns the first derivative. 
    	--          The derivative is computed if it has not been yet.
    	---C++: return const &

    D2(me: in out) returns Vec is static;
    	---Purpose: Returns the second derivative.
    	--          The derivative is computed if it has not been yet.
    	---C++: return const &

    D3(me: in out) returns Vec is static;
    	---Purpose: Returns the third derivative.
    	--          The derivative is computed if it has not been yet.
    	---C++: return const &

    IsTangentDefined(me: in out) returns Boolean is static;
    	---Purpose: Returns True if the tangent is defined.
    	--          For example, the tangent is not defined if the 
    	--          three first derivatives are all null.

    Tangent(me: in out; D : out Dir)
        ---Purpose: output  the tangent direction <D>
	raises  NotDefined
    	    	-- if IsTangentDefined(me)=False.
    	is static;

    Curvature(me: in out)
    	---Purpose: Returns the curvature.
    	returns Real
	raises  NotDefined
    	    	-- if IsTangentDefined(me) == False.
    	is static;

    Normal(me: in out; N : out Dir)
    	---Purpose: Returns the normal direction <N>.
	raises  NotDefined
	    	-- if Curvature(me) < Resolution
	is static;

    CentreOfCurvature(me: in out; P : out Pnt)
    	---Purpose: Returns the centre of curvature <P>.
	raises  NotDefined
	    	-- if Curvature(me) < Resolution
	is static;

fields

    myCurve   : Curve;    -- the Curve on which thw calculus are done
    u         : Real;     -- the current value of the parameter
    level     : Integer;  -- the order of derivation
    cn        : Real;     -- the order of continuity of the Curve
    linTol    : Real;     -- the tolerance for null Vector
    
    pnt       : Pnt;      -- the current point value
    d         : Vec[3];   -- the current first, second and third derivative
                          -- value
    tangent   : Dir;      -- the tangent value
    curvature : Real;     -- the curvature value

    tangentStatus   : Status from LProp; 
                          -- the status of the tangent direction
    significantFirstDerivativeOrder : Integer;
                          -- the order of the first non null derivative
                          -- 
end CLProps;