/*=========================================================================

  Program:   ITK-SNAP
  Module:    $RCSfile: ColorMap.h,v $
  Language:  C++
  Date:      $Date: 2011/04/18 15:06:07 $
  Version:   $Revision: 1.7 $
  Copyright (c) 2007 Paul A. Yushkevich
  
  This file is part of ITK-SNAP

  ITK-SNAP is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.

  -----

  Copyright (c) 2003 Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

  This software is distributed WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.  See the above copyright notices for more information.

=========================================================================*/

#ifndef __ColorMap_h_
#define __ColorMap_h_

#include "itkRGBAPixel.h"
#include "Registry.h"
#include <vector>
#include "itkDataObject.h"
#include "itkObjectFactory.h"
#include "SNAPEvents.h"

/**
 * \class ColorMap
 * \brief This class provides a representation of color maps.
 * A color map is a mapping from the interval [0,1] to the RGBA space. The
 * mapping is piecewise continuous. Where it is continuous, it is linear.
 *
 * The color map is represented as an ordered list of points. Each point has
 * an index value (between 0 and 1). CMPoints may be continuous (i.e., the color
 * map is continuous at the point) and discontinuous. A continuous point has
 * one RGBA value, and discontinuous points have two values. In between points,
 * the color map is interpolated linearly.
 */
class ColorMap : public itk::DataObject
{
public:

  irisITKObjectMacro(ColorMap, itk::Object)

  /** RGBA type */
  typedef unsigned char EltType;
  typedef itk::RGBAPixel<EltType> RGBAType;

  /** Type of point */
  enum CMPointType { CONTINUOUS=0, DISCONTINUOUS };

  /** System presets */
  enum SystemPreset {
    COLORMAP_GREY = 0,
    COLORMAP_JET, COLORMAP_HOT, COLORMAP_COOL,
    COLORMAP_RED, COLORMAP_GREEN, COLORMAP_BLUE,
    COLORMAP_SPRING, COLORMAP_SUMMER,
    COLORMAP_AUTUMN, COLORMAP_WINTER, COLORMAP_COPPER, COLORMAP_HSV,
    COLORMAP_BWR, COLORMAP_RWB, COLORMAP_SPEED, COLORMAP_SPEED_OVERLAY,
    COLORMAP_LEVELSET,
    COLORMAP_CUSTOM
    };

  /** CMPoint representation */
  class CMPoint
  {
  public:

    double m_Index;
    CMPointType m_Type;
    RGBAType m_RGBA[2];

    bool operator==(const CMPoint& rhs) const;
    bool operator!=(const CMPoint& rhs) const;

    CMPoint();

    // Default way to construct color map points starting with SNAP 3.4
    // Alpha equals the position in the color map, i.e., linear alpha across
    // the color map. Points are discontinuous if index is 0/1
    CMPoint(double, EltType r, EltType g, EltType b);

    // Continuous point
    CMPoint(double, EltType r, EltType g, EltType b, EltType a);

    // CMPoint with alpha discontinuity
    CMPoint(double, EltType r, EltType g, EltType b, EltType a1, EltType a2);

    // CMPoint with full discontinuity
    CMPoint(double,
            EltType r1, EltType g1, EltType b1, EltType a1,
            EltType r2, EltType g2, EltType b2, EltType a2);

    // CMPoint copy constructor
    CMPoint(const CMPoint& rhs);
  };

  /**
     * This method maps a value to an RGBA tuple. Values less than 0 and greater
     * than one are accepted, and are mapped to 0 and 1, respecitively.
     */
  RGBAType MapIndexToRGBA(double j) const;

  /**
   * This method initializes the color map to one of the system presets. It
   * is also possible to call this method with COLORMAP_CUSTOM as the parameter,
   * in which case the colormap itself will be unchanged, but will be treated
   * as a custom color map.
   */
  void SetToSystemPreset(SystemPreset preset);


  size_t GetNumberOfCMPoints() const
  { return m_CMPoints.size(); }

  CMPoint GetCMPoint(size_t j) const
  { return m_CMPoints[j]; }

  void UpdateCMPoint(size_t j, const CMPoint &p);

  void DeleteCMPoint(size_t j);

  /**
     * This method inserts a new control point, which is interpolated
     * using the values of the existing points
     */
  size_t InsertInterpolatedCMPoint(double j);

  bool operator==(const ColorMap& rhs) const;

  SystemPreset GetSystemPreset() const
  { return m_CMPreset; }

  /** Get the name of the system preset */
  static const char *GetPresetName(SystemPreset preset);

  void PrintSelf(std::ostream & os, itk::Indent indent) const;

  void SaveToRegistry(Registry &reg);
  void LoadFromRegistry(Registry &reg);

  /**
    * Copy the colormap properties from another colormap into the current
    * colormap.
    */
  void CopyInformation(const itk::DataObject *source);

protected:

  ColorMap();
  virtual ~ColorMap();


private:

  ColorMap(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

  typedef std::vector<CMPoint> CMPointList;
  typedef CMPointList::iterator CMPointIterator;
  typedef CMPointList::const_iterator CMPointConstIterator;

  // Array of points, which must always be sorted by the index
  CMPointList m_CMPoints;

  // Preset
  SystemPreset m_CMPreset;

  // Recomputes internal interpolation terms
  void UpdateInterpolants();

  struct InterpolantData
  { float slope[4], intercept[4]; };
  typedef std::vector<InterpolantData> InterpolantVector;
  InterpolantVector m_Interpolants;

  // Enum for saving presets
  static RegistryEnumMap<SystemPreset> m_ColorMapPresetEnumMap;
};


#endif 


