WCDataScaleHandler.h

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//# WCDataScaleHandler.h: class offering simple data scaling for WorldCanvases
//# Copyright (C) 1993,1994,1995,1996,1998,1999,2000,2001
//# 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 TRIALDISPLAY_WCDATASCALEHANDLER_H
#define TRIALDISPLAY_WCDATASCALEHANDLER_H

#include <casa/aips.h>
#include <casa/Containers/Record.h>
#include <display/Utilities/DisplayOptions.h>

namespace casa { //# NAMESPACE CASA - BEGIN

template <class T> class Array;

// <summary>
// Class implementing simple data scaling for the WorldCanvas.
// </summary>
//  
// <prerequisite>
// <li> Understanding of pseudocolor display of single-channel graphic
// primitives.
// </prerequisite>
//
// <etymology>
// WCDataScaleHandler : WorldCanvas Data Scale Handler
//
// This class is responsible for scaling data into a range suitable
// for display.
// </etymology>
//
// <synopsis>
// WCDataScaleHandler defines a set of functions whose purpose is to 
// transform real data values, such as those from raster images or
// contour lines, into an image whose value ranges from 0 to N-1 for
// some N, normally taken to be the color resolution available for display.
//
// The Display library defines the following process of image display:
// <ol>
// <li> fitting of images to display 
// (<linkto class="WCResampleHandler">WCResampleHandler</linkto>)
// <li> transformation of values from real values to discrete values
// in the range of [0,N-1], where N is the output color resolution.
// (<linkto class="WCDataScaleHandler">WCDataScaleHandler</linkto>)
// <li> translating [0,N-1] into color indicies
// (<linkto class="PixelCanvas">PixelCanvas</linkto>'s mapToColor() function)
// </ol>
// 
// The function suite includes all the normal scalar types.  Default
// implementations exist for
// <ul>
// <li>Bool version which maps False to 0 and True to N-1
// <li>Complex version which extracts magnitude and forwards the
//   call to the Float version.
// <li>DComplex version which extracts magnitude and forwards the
//   call to the Double version.
// </ul>
//
// Each scalar implementation must scale the data according to the 
// domain minimum and maximum values and the N-1 value called the
// rangeMax.
//
// This class would idealy be implemented by a templated member function, but
// C++ does not yet support templated member functions in non-templated
// classes.  Thus the manual expansion-by-type.
// </synopsis>
//
// <motivation>
// Wanted a way for users to customize the scaling process from
// real values to discrete values for color display.
// </motivation>
//
// <example>
// see <linkto class="WCLinearScaleHandler">WCLinearScaleHandler</linkto>
// </example>
//
// <todo>
// <li> add ComplexToRealMethod field to base class to allow
// for extracting values other than magnitude for Complex and DComplex
// variables.
// <li> consider changing Matrices to Arrays to support a Vector of
// transformations.
// </todo>
//

class WCDataScaleHandler : public DisplayOptions {

 public:

  // Default Constructor Required
  WCDataScaleHandler();

  // Destructor (does nothing)
  virtual ~WCDataScaleHandler();

  // Set min/max at construction time
  WCDataScaleHandler(Double min, Double max);

  // op() returns True if the Array in was converted to the
  // Array out successfully.  Default implentation for Bool
  // maps False to 0 and True to rangeMax
  //
  // Types uChar to Double not implemented (They return False).
  // User should override the types needed (or perhaps all
  // depending on your compiler.
  //
  // Default Complex and DComplex extract amplitude and call
  // the Float or Double version.
  // <group>
  virtual Bool operator()(Array<uInt> & out, const Array<Bool> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<uChar> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Char> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<uShort> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Short> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<uInt> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Int> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<uLong> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Long> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Float> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Double> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<Complex> & in);
  virtual Bool operator()(Array<uInt> & out, const Array<DComplex> & in);
  // </group>

  // set/get the min/max to use for the input Array
  // <group>
  Double domainMin() const { return domainMin_; }
  Double domainMax() const { return domainMax_; }
  void setDomainMinMax(Double min, Double max); 
  // </group>

  // set/get the maximum value to use for the output array
  // Note: the minimum value is always zero
  // <group>
  uInt rangeMax() const { return rangeMax_; }
  void setRangeMax(uInt max) { rangeMax_ = max; }
  // </group>

  // install the default options for this DisplayData
  virtual void setDefaultOptions();

  // apply options stored in val to the DisplayData; return value
  // True means a refresh is needed...
  virtual Bool setOptions(Record &rec, Record &recOut);

  // retrieve the current and default options and parameter types.
  virtual Record getOptions();

 private:

  // domain limits to use
  Double domainMin_;
  Double domainMax_;

  // range limits
  // rangeMin is always zero
  uInt rangeMax_;

};


} //# NAMESPACE CASA - END

#endif