// *=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=* 
// ** Copyright UCAR (c) 1990 - 2016                                         
// ** University Corporation for Atmospheric Research (UCAR)                 
// ** National Center for Atmospheric Research (NCAR)                        
// ** Boulder, Colorado, USA                                                 
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// ** the following conditions are met:                                      
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// *=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=* 
/*********************************************************************
 * CircularTemplate.cc: class implementing a circular template to be
 *                      applied on gridded data.
 *
 * RAP, NCAR, Boulder CO
 *
 * January 1999
 *
 * Nancy Rehak
 *
 *********************************************************************/

#include <vector>

#include <math.h>
#include <cstdio>

#include <euclid/CircularTemplate.hh>
#include <euclid/GridOffset.hh>
#include <euclid/GridTemplate.hh>
using namespace std;

/**********************************************************************
 * Constructor
 */

CircularTemplate::CircularTemplate(const double radius) :
  GridTemplate()
{
  setRadius(radius);
}


/**********************************************************************
 * Destructor
 */

CircularTemplate::~CircularTemplate(void)
{
  // Do nothing
}
  

/**********************************************************************
 * printOffsetList() - Print the offset list to the given stream.  This
 *                     is used for debugging.
 */

void CircularTemplate::printOffsetList(FILE *stream)
{
  fprintf(stream, "\n\n");
  fprintf(stream, "Circular template with radius %f grid spaces:\n",
	  _radius);
  
  GridTemplate::printOffsetList(stream);
}


/**********************************************************************
 * setRadius() - Set the radius to the new value.
 */

void CircularTemplate::setRadius(const double radius)
{
  // Save the radius

  _radius = radius;
  
  // Empty out the current offsets list.

  _offsetList.erase(_offsetList.begin(), _offsetList.end());
  
  // Create the offsets list.  If the radius is small, then just make the
  // template cover the current grid square.

  if (radius < 1.0)
  {
    _addOffset(0, 0);
    return;
  }

  for (int y = 0; y <= (int)radius; y++)
  {
    for (int x = 0; x <= (int)radius; x++)
    {
      double double_x = (double)x;
      double double_y = (double)y;
      
      double distance = sqrt((double_x * double_x) + (double_y * double_y));
      
      if (distance <= _radius)
      {
	_addOffset(x, y);
	
	if (x != 0 && y != 0)
	  _addOffset(-x, -y);
	
	if (x != 0)
	  _addOffset(-x, y);
	
	if (y != 0)
	  _addOffset(x, -y);
      }
      
    } /* endfor - x */
    
  } /* endfor - y */
  
}


/**********************************************************************
 *              Private Member Functions                              *
 **********************************************************************/