CLInterpolator2D.h

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// # CLInterpolator2D.h: Abstract base class for interpolator used by CurvedLattice2D
// # Copyright (C) 2003
// # 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 receied 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_CLINTERPOLATOR2D_H
#define LATTICES_CLINTERPOLATOR2D_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/AxesMapping.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
template <class T>
class MaskedLattice;
 
// <summary>
// Abstract base class for interpolator used by CurvedLattice2D.
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="" tests="tCurvedLattice2D.cc">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> <linkto class=CurvedLattice2D>CurvedLattice2D</linkto>
// </prerequisite>
 
// <etymology>
// The CL in CLInterpolator2D means CurvedLattice.
// The 2D means that interpolation in 2 dimensions needs to be done.
// </etymology>
 
// <synopsis>
// CurvedLattice2D needs lattice data which are not on exact grid points.
// Therefore some interpolation scheme is needed. The abstract base class
// CLInterpolation2D makes it possible for CurvedLattice2D to use any
// interpolation scheme.
// Currently the only derived class is
// <linkto class=CLIPNearest2D>CLIPNearest2D</linkto>
// <br>
// Apart from interpolating and returning data, a derived class also has to
// return a mask. For instance, in a possible derived class using
// 4-point interpolation, the interpolation scheme has to take the
// image mask into account, and make a mask for its output data (say that
// the output point is masked off if its 4 input points are masked off).
//
// This base class has some data members defining the lattice and the
// lattice axes to be interpolated. When these data members are set,
// the virtual function <src>preset</src> is called. A derived class
// can implement this function to do some precalculations, etc..
// </synopsis>
 
// <motivation>
// This class makes it possible to hide the interpolation to be used
// from the CurvedLattice2D class.
// </motivation>
 
template <class T>
class CLInterpolator2D {
 public:
  CLInterpolator2D() : itsLatticePtr(0) { ; }
 
  virtual ~CLInterpolator2D();
 
  // Let a derived class make a copy of itself.
  virtual CLInterpolator2D<T>* clone() const = 0;
 
  // Set the internals to the values of the CurvedLattice using it.
  // Note that only a copy of the lattice pointer is made.
  // Thereafter the virtual function preset() is called to give a derived
  // class the opportunity to do some initial work.
  void set(MaskedLattice<T>* lattice, const AxesMapping& axesMap, uInt axis1, uInt axis2,
           uInt curveAxis);
 
  // Get the data for the given pixel points (on axis1 and axis2) and
  // the chunk in the other axes as given by the section.
  // The Slicer is fixed and the buffer has the correct shape.
  virtual void getData(Array<T>& buffer, const Vector<Float>& x, const Vector<Float>& y,
                       const Slicer& section) = 0;
 
  // Get the mask for the given pixel points (on axis1 and axis2) and
  // the chunk in the other axes as given by the section.
  // The Slicer is fixed and the buffer has the correct shape.
  virtual void getMask(Array<Bool>& buffer, const Vector<Float>& x, const Vector<Float>& y,
                       const Slicer& section) = 0;
 
 protected:
  // Copy constructor can only be used by derived classes.
  CLInterpolator2D(const CLInterpolator2D<T>&);
 
  // Assignment can only be used by derived classes.
  CLInterpolator2D& operator=(const CLInterpolator2D<T>&);
 
  // Let a derived class do some initial work after set is called.
  // The default implementation does nothing.
  virtual void preset();
 
  MaskedLattice<T>* itsLatticePtr;
  AxesMapping itsAxesMap;
  uInt itsAxis1;
  uInt itsAxis2;
  uInt itsCurveAxis;
  Bool itsIsRef;  // True = lattice returns array reference
};
 
}  // namespace casacore
 
#ifndef CASACORE_NO_AUTO_TEMPLATES
#include <casacore/lattices/LatticeMath/CLInterpolator2D.tcc>
#endif  // # CASACORE_NO_AUTO_TEMPLATES
#endif