LELRegion.h

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// # LELRegion.h:  Class to hold a region as a LEL node
// # Copyright (C) 1999
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef LATTICES_LELREGION_H
#define LATTICES_LELREGION_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/lattices/LEL/LELInterface.h>
#include <casacore/lattices/LRegions/LatticeRegion.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class LattRegionHolder;
 
// <summary>
// Class to hold a region as a LEL node
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class="Lattice"> Lattice</linkto>
//   <li> <linkto class="LatticeExpr"> LatticeExpr</linkto>
//   <li> <linkto class="LatticeExprNode"> LatticeExprNode</linkto>
//   <li> <linkto class="LELInterface"> LELInterface</linkto>
// </prerequisite>
 
// <etymology>
// This derived LEL letter class handles regions.
// </etymology>
 
// <synopsis>
// This LEL letter class is derived from LELInterface.  It
// is used to construct LEL objects from regions.
// The internal region is an <linkto class=ImageRegion>ImageRegion</linkto>
// object, thus the region can be of any type.
// With operator [] a region is applied to an image (expression).
// At that stage possible world coordinates are converted to lattice
// coordinates.
// <p>
// The attributes of a LELRegion object define an empty shape,
// because in general the shape of a region is only known after
// it is applied to an image.
// <p>
// A description of the implementation details of the LEL classes can
// be found in
// <a href="../notes/216.html">Note 216</a>
// </synopsis>
 
// <motivation>
// We needed to be able to handle regions in a LEL expression.
// </motivation>
 
// # <todo asof="1998/01/21">
// # </todo>
 
class LELRegion : public LELInterface<Bool> {
 public:
  // Constructor.
  LELRegion(const LattRegionHolder& region);
 
  // Constructor. It takes over the pointer.
  LELRegion(LattRegionHolder* region);
 
  // Destructor.
  ~LELRegion();
 
  // Get a pointer to the region object.
  const LattRegionHolder& region() const { return *region_p; }
 
  // Getting region data cannot be done (throws an exception).
  virtual void eval(LELArray<Bool>&, const Slicer&) const;
 
  // Getting region data cannot be done (throws an exception).
  virtual LELScalar<Bool> getScalar() const;
 
  // Do further preparations (e.g. optimization) on the expression.
  virtual Bool prepareScalarExpr();
 
  // Get class name
  virtual String className() const;
 
  // Form a compound from the regions.
  // <group>
  static LELRegion* makeUnion(const LELInterface<Bool>& left, const LELInterface<Bool>& right);
  static LELRegion* makeIntersection(const LELInterface<Bool>& left,
                                     const LELInterface<Bool>& right);
  static LELRegion* makeDifference(const LELInterface<Bool>& left, const LELInterface<Bool>& right);
  static LELRegion* makeComplement(const LELInterface<Bool>& expr);
  // </group>
 
 private:
  // Get the LattRegionHolder after checking that the expression is a region.
  static const LattRegionHolder& region(const LELInterface<Bool>& expr);
 
  // Check if both regions have the same type (pixel or world) and if
  // no LCSlicer type of region is used.
  static void checkTypes(const LattRegionHolder& left, const LattRegionHolder& right);
 
  // Member variables.
  LattRegionHolder* region_p;
};
 
// <summary>
// Class to convert a region to a boolean node
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class="LELRegion"> Lattice</linkto>
//   <li> <linkto class="LatticeExprNode"> LatticeExprNode</linkto>
//   <li> <linkto class="LELInterface"> LELInterface</linkto>
// </prerequisite>
 
// <etymology>
// This derived LEL letter class handles a region as a boolean lattice.
// </etymology>
 
// <synopsis>
// This class makes it possible to handle a region as a true
// boolean lattice without the need to apply the region to an image.
// It means that it is only possible if the region has absolute
// lattice coordinates.
// <p>
// A description of the implementation details of the LEL classes can
// be found in
// <a href="../notes/216.html">Note 216</a>
// </synopsis>
 
// <motivation>
// It is useful to be able to handle a mask as a boolean lattice.
// </motivation>
 
// # <todo asof="1998/01/21">
// # </todo>
 
class LELRegionAsBool : public LELInterface<Bool> {
 public:
  // Constructor.
  LELRegionAsBool(const LELRegion& region);
 
  // Destructor.
  ~LELRegionAsBool();
 
  // Get region data.
  virtual void eval(LELArray<Bool>& result, const Slicer& section) const;
 
  // Getting region data as a scalar cannot be done (throws an exception).
  virtual LELScalar<Bool> getScalar() const;
 
  // Do further preparations (e.g. optimization) on the expression.
  virtual Bool prepareScalarExpr();
 
  // Get class name
  virtual String className() const;
 
 private:
  // Member variables.
  LatticeRegion region_p;
};
 
}  // namespace casacore
 
#endif