-- File:	MgtTopLoc.cdl
-- Created:	Wed Mar  3 18:39:33 1993
-- Author:	Remi LEQUETTE
--		<rle@phobox>
-- Update:      Frederic MAUPAS
--              <fma@pronox>
---Copyright:	 Matra Datavision 1993


package MgtTopLoc 

	---Purpose: The package  MgtTopLoc provides methods   to store
	--          and retrieve local    coordinate    systems.  i.e.
	--          translationg them from Persistent to Transient and
	--          vice-versa. 
	--          
	--          * Persistent local coordinate systems are provided
	--          by the package PTopLoc.
	--          
	--          * Transient local  coordinate systems are provided
	--          by the package TopLoc.
	--          
	--          This package keeps  track of previous translations
	--          to preserve the incremental  feature of coordinate
	--          systems. i.e.  once a  data  has  been translated,
	--          translating it back will give the original data.
	--          
	--          Two kinds of objects are managed :
	--          
	--          *   Datum3D :  A  Datum3D   is an elementary local
	--          coordinate system handled by reference.
	--          
	--          *  Location   : A Location   is  a  complex  local
	--          coordinate system   made   by  linking  elementary
	--          coordinate systems  (Datum3D).  If  a Location  is
	--          translated twice only the local coordinate systems
	--          will be the same.  This  is not a problem  as  the
	--          comparison of Locations is based on the comparison
	--          of local coordinate systems.

uses

    TopLoc,
    PTopLoc,
    PTColStd
    
is
    Translate(D : Datum3D from TopLoc;
    	      M : in out TransientPersistentMap from PTColStd) 
    returns Datum3D from PTopLoc;
	---Purpose: Translate a  transient   Datum3D to  a  persistant
	--          Datum3D.
	---Level: Internal 
	
    Translate(D : Datum3D from PTopLoc;
    	      M : in out PersistentTransientMap from PTColStd)
    returns Datum3D from TopLoc;
	---Purpose: Translate a  persistant   Datum3D to  a  transient
	--          Datum3D.
	---Level: Internal 
	
	
    Translate(L : Location from TopLoc;
    	      M : in out TransientPersistentMap from PTColStd)  
    returns Location from PTopLoc;
	---Purpose: Translate a non  storable  Location to  a storable
	--          Location.
	---Level: Internal 
	
    Translate(L : Location from PTopLoc;
    	      M : in out PersistentTransientMap from PTColStd)   
    returns Location from TopLoc;
	---Purpose: Translate a storable  Location  to a non  storable
	--          Location.
	---Level: Internal 	
    

end MgtTopLoc;