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

  Program: GDCM (Grassroots DICOM). A DICOM library

  Copyright (c) 2006-2011 Mathieu Malaterre
  All rights reserved.
  See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html 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 notice for more information.

=========================================================================*/
#include "gdcmOrientation.h"

#include <cmath>

namespace gdcm
{

Orientation::Orientation() {}
Orientation::~Orientation() {}

void Orientation::Print(std::ostream &os) const
{
  os << "ObliquityThresholdCosineValue: " << ObliquityThresholdCosineValue;
}

static const char *OrientationStrings[] = {
  "UNKNOWN",
  "AXIAL",
  "CORONAL",
  "SAGITTAL",
  "OBLIQUE",
  NULL
};

// http://public.kitware.com/pipermail/insight-users/2005-March/012246.html
// 0.5477 would be the square root of 1 (unit vector sum of squares) divided by 3 (oblique axes - a "double" oblique)
// 0.7071 would be the square root of 1 (unit vector sum of squares) divided by 2 (oblique axes)
double Orientation::ObliquityThresholdCosineValue = 0.8;
//const double Orientation::obliquityThresholdCosineValue = 0.7071;
char Orientation::GetMajorAxisFromPatientRelativeDirectionCosine(double x, double y, double z)
{
  char axis = 0;

  const char orientationX = x < 0 ? 'R' : 'L';
  const char orientationY = y < 0 ? 'A' : 'P';
  const char orientationZ = z < 0 ? 'F' : 'H';

  const double absX = std::fabs(x);
  const double absY = std::fabs(y);
  const double absZ = std::fabs(z);

  // The tests here really don't need to check the other dimensions,
  // just the threshold, since the sum of the squares should be == 1.0
  // but just in case ...

  if (absX>ObliquityThresholdCosineValue && absX>absY && absX>absZ)
    {
    axis = orientationX;
    }
  else if (absY>ObliquityThresholdCosineValue && absY>absX && absY>absZ)
    {
    axis = orientationY;
    }
  else if (absZ>ObliquityThresholdCosineValue && absZ>absX && absZ>absY)
    {
    axis = orientationZ;
    }
  else
    {
    // nothing
    }
  return axis;
}

void   Orientation::SetObliquityThresholdCosineValue(double val)
{
  Orientation::ObliquityThresholdCosineValue = val;
}

double Orientation::GetObliquityThresholdCosineValue()
{
  return Orientation::ObliquityThresholdCosineValue;
}

Orientation::OrientationType Orientation::GetType(const double dircos[6])
{
  OrientationType type = Orientation::UNKNOWN;
  if( dircos )
    {
    char rowAxis = GetMajorAxisFromPatientRelativeDirectionCosine(dircos[0],dircos[1],dircos[2]);
    char colAxis = GetMajorAxisFromPatientRelativeDirectionCosine(dircos[3],dircos[4],dircos[5]);
    if (rowAxis != 0 && colAxis != 0 )
      {
      if      ((rowAxis == 'R' || rowAxis == 'L') && (colAxis == 'A' || colAxis == 'P')) type = Orientation::AXIAL;
      else if ((colAxis == 'R' || colAxis == 'L') && (rowAxis == 'A' || rowAxis == 'P')) type = Orientation::AXIAL;

      else if ((rowAxis == 'R' || rowAxis == 'L') && (colAxis == 'H' || colAxis == 'F')) type = Orientation::CORONAL;
      else if ((colAxis == 'R' || colAxis == 'L') && (rowAxis == 'H' || rowAxis == 'F')) type = Orientation::CORONAL;

      else if ((rowAxis == 'A' || rowAxis == 'P') && (colAxis == 'H' || colAxis == 'F')) type = Orientation::SAGITTAL;
      else if ((colAxis == 'A' || colAxis == 'P') && (rowAxis == 'H' || rowAxis == 'F')) type = Orientation::SAGITTAL;
      }
    else
      {
      type = Orientation::OBLIQUE;
      }
    }
  return type;
}

const char *Orientation::GetLabel(OrientationType type)
{
  return OrientationStrings[type];
}


}
