LCStretch.h

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//# LCStretch.h: Stretch length 1 axes in an LCRegion along straight lines
//# Copyright (C) 2001
//# 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: aips2-request@nrao.edu.
//#        Postal address: AIPS++ Project Office
//#                        National Radio Astronomy Observatory
//#                        520 Edgemont Road
//#                        Charlottesville, VA 22903-2475 USA
//#
//# $Id$

#ifndef LATTICES_LCSTRETCH_H
#define LATTICES_LCSTRETCH_H

//# Includes
#include <casacore/casa/aips.h>
#include <casacore/lattices/LRegions/LCRegionMulti.h>
#include <casacore/lattices/LRegions/LCBox.h>


namespace casacore { //# NAMESPACE CASACORE - BEGIN

// <summary>
// Stretch length 1 axes in an LCRegion along straight lines
// </summary>

// <use visibility=export>

// <reviewed reviewer="" date="" tests="">
// </reviewed>

// <prerequisite>
//   <li> <linkto class=LCRegion>LCRegion</linkto>
// </prerequisite>

// <synopsis> 
// The LCStretch class is a specialization of class
// <linkto class=LCRegion>LCRegion</linkto>.
// It makes it possible to stretch a LCRegion along straight lines to
// other dimensions. E.g. a circle in the xy-plane can be stretched to
// a cylinder in the xyz-space.
// It can be used for a lattice of any dimensionality as long as the
// dimensionality of the (hyper-)stretch matches the dimensionality of
// the lattice.
// </synopsis> 

// <example>
// <srcblock>
// </srcblock>
// </example>

// <todo asof="1997/11/11">
// <li> Stretch along (slanted) cone lines
// </todo>

class LCStretch: public LCRegionMulti
{
public:
    LCStretch();

    // Stretch the given region along axes as given by <src>stretchAxes</src>
    // from the bottom left corner (blc) to the top right corner (trc)
    // as given by <src>stretchBox</src>.
    // The axes to be stretched need to have length 1 in the original region.
    // Every kind of box (absolute, relative, fractional, unspecified)
    // can be used to define the stretch blc and trc.
    // The dimensionality of the LCStretch region is the same as the
    // dimensionality of the original region.
    // <br>
    // The second version takes over the pointer when the switch is true.
    // <group> 
    LCStretch (const LCRegion& region,
               const IPosition& stretchAxes,
               const LCBox& stretchBox);
    LCStretch (Bool takeOver,
               const LCRegion* region,
               const IPosition& stretchAxes,
               const LCBox& stretchBox);
    // </group>

    // Copy constructor (copy semantics).
    LCStretch (const LCStretch& other);

    virtual ~LCStretch();

    // Assignment (copy semantics).
    LCStretch& operator= (const LCStretch& other);

    // Comparison
    virtual Bool operator== (const LCRegion& other) const;
 
    // Make a copy of the derived object.
    virtual LCRegion* cloneRegion() const;

    // Get the original region.
    const LCRegion& region() const;
    
     // Get the stretch axes.
    const IPosition& stretchAxes() const;

    // Get the stretch box.
    const LCBox& stretchBox() const;

    // Get the class name (to store in the record).
    static String className();

    // Get the region type.  Returns the class name.
    virtual String type() const;
 
    // Convert the (derived) object to a record.
    virtual TableRecord toRecord (const String& tableName) const;

    // Convert correct object from a record.
    static LCStretch* fromRecord (const TableRecord&,
                                  const String& tableName);

protected:
    // Construct another LCRegion (for e.g. another lattice) by moving
    // this one. It recalculates the bounding box and mask.
    // A positive translation value indicates "to right".
    virtual LCRegion* doTranslate (const Vector<Float>& translateVector,
                                   const IPosition& newLatticeShape) const;

    // Do the actual getting of the mask.
    virtual void multiGetSlice (Array<Bool>& buffer, const Slicer& section);

    // This function is needed here because the niceCursorShape of the
    // contributing region does not make any sense (other dimensionality). 
    virtual IPosition doNiceCursorShape (uInt maxPixels) const;

private:
    // Fill the object.
    void fill (const IPosition& stretchAxes, const LCBox& stretchBox);


    IPosition itsStretchAxes;
    LCBox     itsStretchBox;
};


inline const LCRegion& LCStretch::region() const
{
    return *(regions()[0]);
}
inline const IPosition& LCStretch::stretchAxes() const
{
    return itsStretchAxes;
}
inline const LCBox& LCStretch::stretchBox() const
{
    return itsStretchBox;
}



} //# NAMESPACE CASACORE - END

#endif