-- Created on: 1993-03-09
-- Created by: JCV
-- Copyright (c) 1993-1999 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.

class Axis2Placement from Geom inherits AxisPlacement from Geom

        ---Purpose :  Describes a right-handed coordinate system in 3D space.
    	-- A coordinate system is defined by:
    	-- - its origin, also termed the "Location point" of the coordinate system,
    	-- - three orthogonal unit vectors, termed respectively
    	--   the "X Direction", "Y Direction" and "Direction" (or
    	--   "main Direction") of the coordinate system.
    	-- As a Geom_Axis2Placement coordinate system is
    	-- right-handed, its "Direction" is always equal to the
    	-- cross product of its "X Direction" and "Y Direction".
    	-- The "Direction" of a coordinate system is called the
    	-- "main Direction" because when this unit vector is
    	-- modified, the "X Direction" and "Y Direction" are
    	-- recomputed, whereas when the "X Direction" or "Y
    	-- Direction" is changed, the "main Direction" is
    	-- retained. The "main Direction" is also the "Z Direction".
    	-- Note: Geom_Axis2Placement coordinate systems
    	-- provide the same kind of "geometric" services as
    	-- gp_Ax2 coordinate systems but have more complex
    	-- data structures. The geometric objects provided by
    	-- the Geom package use gp_Ax2 objects to include
    	-- coordinate systems in their data structures, or to
    	-- define the geometric transformations, which are applied to them.
    	-- Geom_Axis2Placement coordinate systems are
    	-- used in a context where they can be shared by
    	-- several objects contained inside a common data structure.


uses Ax1      from gp,
     Ax2      from gp,
     Dir      from gp,
     Pnt      from gp,
     Trsf     from gp,
     Geometry from Geom

raises ConstructionError from Standard

is


  Create (A2 : Ax2)  returns Axis2Placement;
        ---Purpose : Returns a transient copy of A2.


  Create (P : Pnt; N, Vx : Dir)   returns Axis2Placement
	---Purpose :
        --  P is the origin of the axis placement, N is the main
        --  direction of the axis placement and Vx is the "XDirection".
        --  If the two directions N and Vx are not orthogonal the 
        --  "XDirection" is computed as follow :
        --  XDirection = N ^ (Vx ^ N). 
     raises ConstructionError;
        ---Purpose : Raised if N and Vx are parallel.


 

  SetAx2 (me : mutable; A2 : Ax2);
        ---Purpose : Assigns the origin and the three unit vectors of A2 to
    	-- this coordinate system.
      


  SetDirection (me : mutable; V : Dir)
        ---Purpose :
        --  Changes the main direction of the axis placement.
        --  The "Xdirection" is modified :
        --  New XDirection = V ^ (Previous_Xdirection ^ V).
     raises ConstructionError;
        ---Purpose :
        --  Raised if V and the previous "XDirection" are parallel 
        --  because it is impossible to calculate the new "XDirection"
        --  and the new "YDirection".


  SetXDirection (me : mutable; Vx : Dir)
        ---Purpose :
        --  Changes the "XDirection" of the axis placement, Vx is the 
        --  new "XDirection". If Vx is not normal to the main direction
        --  then "XDirection" is computed as follow : 
        --  XDirection = Direction ^ ( Vx ^ Direction).
        --  The main direction is not modified.
     raises ConstructionError;
        ---Purpose :  Raised if Vx and "Direction"  are parallel.


  SetYDirection (me : mutable; Vy : Dir)
        ---Purpose :
        --  Changes the "YDirection" of the axis placement, Vy is the 
        --  new "YDirection". If Vy is not normal to the main direction
        --  then "YDirection" is computed as follow : 
        --  YDirection = Direction ^ ( Vy ^ Direction).
        --  The main direction is not modified. The "XDirection" is
        --  modified.
     raises ConstructionError;
        ---Purpose : Raised if Vy and the main direction are parallel.


  Ax2 (me)  returns Ax2;
        ---Purpose : Returns a non transient copy of <me>.


  XDirection (me)   returns Dir;
   	---Purpose : Returns the "XDirection". This is a unit vector.
    	---C++: return const&


  YDirection (me)  returns Dir;
  	---Purpose : Returns the "YDirection". This is a unit vector.
    	---C++: return const&




  Transform (me : mutable; T : Trsf);
        ---Purpose :  
        --  Transforms an axis placement with a Trsf.
        --  The "Location" point, the "XDirection" and the
        --  "YDirection" are transformed with T.  The resulting
        --  main "Direction" of <me> is the cross product between 
        --  the "XDirection" and the "YDirection" after transformation.



  Copy (me)  returns like me;
    	---Purpose: Creates a new object which is a copy of this coordinate system.


  Create (P : Pnt; Vz, Vx, Vy : Dir)   returns Axis2Placement
     is private;


fields

  vxdir : Dir;
  vydir : Dir;


end;