0025584: Wrong result obtained by PerformInfinitePoint Test

[occt.git] / src / BRepAlgoAPI / BRepAlgoAPI_Section.cdl

-- Created on: 1994-02-18
-- Created by: Remi LEQUETTE
-- Copyright (c) 1994-1999 Matra Datavision
-- Copyright (c) 1999-2014 OPEN CASCADE SAS
--
-- This file is part of Open CASCADE Technology software library.
--
-- This library is free software; you can redistribute it and/or modify it under
-- the terms of the GNU Lesser General Public License version 2.1 as published
-- by the Free Software Foundation, with special exception defined in the file
-- OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-- distribution for complete text of the license and disclaimer of any warranty.
--
-- Alternatively, this file may be used under the terms of Open CASCADE
-- commercial license or contractual agreement.

-- modified by Michael KLOKOV  Wed Mar  6 15:01:25 2002

class Section from BRepAlgoAPI  
    inherits BooleanOperation from BRepAlgoAPI

     ---Purpose: Computes the intersection of two shapes or geometries.
     -- Geometries can be surfaces of planes.
     -- Geometries are converted to faces
     -- When a geometry has been converted to
     -- topology the created shape can be found using
     -- the methods Shape1 and Shape2 inherited from the class BooleanOperation.
     -- The result (Shape() method) is a compound containing 
     -- edges built on intersection curves.
     -- By default, the section is performed immediatly in 
     -- class constructors, with default values :
     -- - geometries built are NOT approximated.
     -- - PCurves are NOT computed on both parts.
     -- Example : giving two shapes S1,S2 accessing faces,
     -- let compute the section edges R on S1,S2, 
     -- performing approximation on new curves,
     -- performing PCurve on part 1 but not on part 2 :
     -- Standard_Boolean PerformNow = Standard_False;
     -- BRepBoolAPI_Section S(S1,S2,PerformNow);
     -- S.ComputePCurveOn1(Standard_True);
     -- S.Approximation(Standard_True);
     -- S.Build();
     -- TopoDS_Shape R = S.Shape();
     -- On Null Shapes of geometries, NotDone() is called. 

uses
    Pln   from gp,
    Shape from TopoDS,
    Surface from Geom,
    Curve   from Geom2d,
    PaveFiller from BOPAlgo,
    ListOfShape from TopTools
    
is
    Create 
        returns Section from BRepAlgoAPI;   
    ---C++: alias "Standard_EXPORT virtual ~BRepAlgoAPI_Section();"  
    --- Purpose: Empty constructor 
        
 
    Create (S1,S2 : Shape from TopoDS; 
            aDSF:PaveFiller from BOPAlgo;
            PerformNow : Boolean = Standard_True)  
        returns Section from BRepAlgoAPI;
    

    Create(Sh1,Sh2 : Shape from TopoDS;
            PerformNow : Boolean = Standard_True) 
        returns Section from BRepAlgoAPI;
    ---Purpose: see upper
    ---Level: Public
     

    Create(Sh : Shape from TopoDS;  
            Pl : Pln from gp;
            PerformNow : Boolean = Standard_True) 
        returns Section from BRepAlgoAPI;
     ---Purpose: see upper
     ---Level: Public
     

    Create(Sh : Shape from TopoDS;  
            Sf : Surface from Geom;
            PerformNow : Boolean = Standard_True) 
        returns Section from BRepAlgoAPI;
     ---Purpose: see upper
     ---Level: Public
     

    Create(Sf : Surface from Geom;  
            Sh : Shape from TopoDS;
            PerformNow : Boolean = Standard_True) 
        returns Section from BRepAlgoAPI;
     ---Purpose: see upper
     ---Level: Public
 
    Create(Sf1 : Surface from Geom;  
            Sf2 : Surface from Geom;
            PerformNow : Boolean = Standard_True) 
        returns Section from BRepAlgoAPI;
     ---Purpose: This and the above classes construct a framework for
     -- computing the section lines of:
     -- -       two shapes Sh1 and Sh2, or
     -- -       shape Sh and plane Pl,  or
     -- -       shape Sh and surface Sf, or
     -- -       surface Sf and shape Sh, or
     -- -       two surfaces Sf1 and Sf2,
     --   and builds a result if PerformNow equals true, its
     -- default value. If PerformNow equals false, the intersection
     -- will be computed later by the function Build.
     --  The constructed shape will be returned by the function Shape.
     -- This is a compound object composed of edges. These
     -- intersection edges may be built:
     -- -      on new intersection lines, or
     -- -      on coincident portions of edges in the two intersected    shapes.
     --   These intersection edges are independent: they are not
     -- chained or grouped in wires. If no intersection edge exists, the
     -- result is an empty compound object.
     -- Note that other objects than TopoDS_Shape shapes involved in
     -- these syntaxes are converted into faces or shells before
     -- performing the computation of the intersection. A shape
     -- resulting from this conversion can be retrieved with the
     -- function Shape1 or Shape2.
     -- Parametric 2D curves on intersection edges
     -- No parametric 2D curve (pcurve) is defined for each elementary
     -- edge of the result. To attach such parametric curves to the
     -- constructed edges you may use a constructor with the PerformNow
     -- flag equal to false; then you use:
     -- -      the function ComputePCurveOn1 to ask for
     --    the additional computation of a pcurve in the parametric
     --    space of the first shape,
     -- -      the function ComputePCurveOn2 to ask for
     --    the additional computation of a pcurve in the parametric
     --    space of the second shape, in the end,
     -- -      the function Build to construct the result.
     --   Approximation of intersection edges
     --   The underlying 3D geometry attached to each elementary edge
     -- of the result is:
     -- -       analytic where possible, provided the corresponding
     --    geometry corresponds to a type of analytic curve
     --    defined in the Geom package; for example, the intersection
     --    of a cylindrical shape with a plane gives an ellipse or a    circle;
     -- -       or elsewhere, given as a succession of points grouped
     --    together in a BSpline curve of degree 1.
     -- If you prefer to have an attached 3D geometry which is a
     -- BSpline approximation of the computed set of points on
     -- computed elementary intersection edges whose underlying geometry
     -- is not analytic, you may use a constructor with the PerformNow
     -- flag equal to false. Then you use:
     -- -      the function Approximation to ask for this
     --    computation option, and
     -- -      the function Build to construct the result.
     -- -      Note that as a result, approximations will only be
     --    computed on edges built on new intersection lines.
     -- -      Example
     -- You may also combine these computation options. In the following example:
     -- - each elementary edge of the computed intersection,
     --   built on a new intersection line, which does not
     --  correspond to an analytic Geom curve, will be approximated by
     --   a BSpline curve whose degree is not greater than 8.
     -- - each elementary edge built on a new intersection line, will have:
     -- - a pcurve in the parametric space of the intersected face of shape S1,
     -- - no pcurve in the parametric space of the intersected face of shape S2.
     --       // TopoDS_Shape S1 = ... , S2 = ... ;
     -- Standard_Boolean PerformNow = Standard_False;
     -- BRepAlgoAPI_Section S ( S1, S2, PerformNow );
     -- S.ComputePCurveOn1 (Standard_True);
     -- S.Approximation (Standard_True);
     -- S.Build();
     -- TopoDS_Shape R = S.Shape();
 

    Init1(me : out; 
            S1 : Shape from TopoDS);
     ---Purpose: initialize first part
     ---Level: Public
 
    Init1(me : out; 
            Pl : Pln from gp);
     ---Purpose: initialize first part
     ---Level: Public
 
    Init1(me : out; 
            Sf : Surface from Geom);
     ---Purpose: initialize first part
     ---Level: Public
 
    Init2(me : out; 
            S2 : Shape from TopoDS);
     ---Purpose: initialize second part
     ---Level: Public
 
    Init2(me : out; 
            Pl : Pln from gp);
     ---Purpose: initialize second part
     ---Level: Public
 
    Init2(me : out; 
            Sf : Surface from Geom);
     ---Purpose: Reinitializes the first and the
     -- second parts on which this algorithm is going to perform
     -- the intersection computation. This is done with either: the
     -- surface Sf, the plane Pl or the shape Sh.
     -- You use the function Build to construct the result.
 
    Approximation(me : out; 
        B : Boolean from Standard);
     ---Level: Public
     ---Purpose: Defines an option for computation
     -- of further intersections. This computation will be performed by
     -- the function Build in this framework.
     -- By default, the underlying 3D geometry attached to each
     -- elementary edge of the result of a computed intersection is:
     -- - analytic where possible, provided the corresponding
     --    geometry corresponds to a type of analytic curve defined in
     --    the Geom package; for example the intersection of a
     --    cylindrical shape with a plane gives an ellipse or a circle;
     -- -      or elsewhere, given as a succession of points grouped
     -- together in a BSpline curve of degree 1. If Approx equals
     -- true, when further computations are performed in this framework
     -- with the function Build, these edges will have an attached 3D
     --    geometry which is a BSpline approximation of the computed
     --    set of points.
     --   Note that as a result, approximations will be computed
     -- on edges built only on new intersection lines.
 
    ComputePCurveOn1(me : out; 
        B : Boolean from Standard);
     ---Level: Public
     ---Purpose: 
     -- Indicates if the Pcurve must be (or not) performed on first part. 

    ComputePCurveOn2(me : out; 
            B : Boolean from Standard);
     ---Level: Public
     ---Purpose: Define options for the computation of further
     -- intersections, which will be performed by the function Build
     -- in this framework.
     -- By default, no parametric 2D curve (pcurve) is defined for the
     -- elementary edges of the result. If ComputePCurve1 equals true,
     -- further computations performed in this framework with the function
     -- Build will attach an additional pcurve in the parametric space of
     -- the first shape to the constructed edges.
     -- If ComputePCurve2 equals true, the additional pcurve will be
     -- attached to the constructed edges in the parametric space of the
     -- second shape.
     -- These two functions may be used together.
 
    Build(me : in out) 
        is redefined;
     ---Purpose:  Performs the computation of
     -- section lines between two parts defined at the time of
     -- construction of this framework or reinitialized with the Init1 and
     -- Init2 functions.
     -- The constructed shape will be returned by the function Shape.
     -- This is a compound object composed of edges. These
     -- intersection edges may be built:
     -- -      on new intersection lines, or
     -- -      on coincident portions of edges in the two intersected shapes.
     -- These intersection edges are independent: they are not chained
     -- or grouped into wires.
     -- If no intersection edge exists, the result is an empty compound object.
     -- The shapes involved in the construction of section lines can
     -- be retrieved with the function Shape1 or Shape2. Note that other
     -- objects than TopoDS_Shape shapes given as arguments at the
     -- construction time of this framework, or to the Init1 or
     -- Init2 function, are converted into faces or shells before
     -- performing the computation of the intersection.
     -- Parametric 2D curves on intersection edges
     -- No parametric 2D curve (pcurve) is defined for the elementary
     -- edges of the result. To attach parametric curves like this to
     -- the constructed edges you have to use:
     -- -      the function
     -- ComputePCurveOn1 to ask for the additional computation of a
     -- pcurve in the parametric space of the first shape,
     -- -      the function
     --    ComputePCurveOn2 to ask for the additional computation of a
     --    pcurve in the parametric space of the second shape.
     -- This must be done before calling this function.
     --   Approximation of intersection edges
     -- The underlying 3D geometry attached to each elementary edge of the result is:
     -- -      analytic (where possible) provided the corresponding
     -- geometry corresponds to a type of analytic curve defined in
     --    the Geom package; for example, the intersection of a
     --    cylindrical shape with a plane gives an ellipse or a circle;    or
     -- -      elsewhere, given as a succession of points grouped
     --    together in a BSpline curve of degree 1.
     --   If, on computed elementary intersection edges whose
     -- underlying geometry is not analytic, you prefer to have an
     -- attached 3D geometry which is a Bspline approximation of the
     -- computed set of points, you have to use the function Approximation
     -- to ask for this computation option before calling this function.
     -- You may also have combined these computation options: look at the
     -- example given above to illustrate the use of the constructors.
     

    HasAncestorFaceOn1(me;  
            E : Shape from TopoDS;
            F : out Shape from TopoDS)
        returns Boolean from Standard;
     ---Level: Public
     ---Purpose:
     -- get the face of the first part giving section edge <E>.
     -- Returns True on the 3 following conditions :
     -- 1/ <E> is an edge returned by the Shape() method. 
     -- 2/ First part of section performed is a shape.
     -- 3/ <E> is built on a intersection curve (i.e <E>
     --   is not the result of common edges)
     -- When False, F remains untouched.

    HasAncestorFaceOn2(me;  
            E : Shape from TopoDS;
            F : out Shape from TopoDS)
        returns Boolean from Standard;
     ---Purpose:  Identifies the ancestor faces of
     -- the intersection edge E resulting from the last
     -- computation performed in this framework, that is, the faces of
     -- the two original shapes on which the edge E lies:
     -- -      HasAncestorFaceOn1 gives the ancestor face in the first shape, and
     -- -      HasAncestorFaceOn2 gives the ancestor face in the second shape.
     --   These functions return true if an ancestor face F is found, or false if not.
     --   An ancestor face is identifiable for the edge E if the following
     -- conditions are satisfied:
     -- -  the first part on which this algorithm performed its
     --    last computation is a shape, that is, it was not given as
     -- a surface or a plane at the time of construction of this
     -- algorithm or at a later time by the Init1 function,
     -- - E is one of the elementary edges built by the
     -- last computation of this section algorithm.
     -- To use these functions properly, you have to test the returned
     -- Boolean value before using the ancestor face: F is significant
     -- only if the returned Boolean value equals true.

    InitParameters(me: out) 
        is private;
    ---Level: Private
     

fields
    myshapeisnull       : Boolean from Standard;
    myparameterschanged : Boolean from Standard;
    myApprox            : Boolean from Standard;
    myComputePCurve1    : Boolean from Standard;
    myComputePCurve2    : Boolean from Standard;
    
end Section from BRepAlgoAPI;