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/* ** Copyright UCAR (c) 1990 - 2016                                         */
/* ** University Corporation for Atmospheric Research (UCAR)                 */
/* ** National Center for Atmospheric Research (NCAR)                        */
/* ** Boulder, Colorado, USA                                                 */
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/* get_intervals.c - get intervals in a row or interval */

#include <stdio.h>
#include <sys/types.h>
#include <euclid/clump.h>

/*
 * Determine the set of intervals between begin and end in the array row
 * which are above threshold and store the results in interval_array.
 *
 * Inputs:
 *  	row 		- array of bytes to examine
 * 	begin		- beginning of data to examine in row
 * 	end		- end of data to examine in row
 *  	threshold	- the given threshold
 *
 * Outputs:
 * 	the intervals found are stored in interval_array
 *
 * Returns:
 *  	the number of intervals found
 */
int
EG_get_intervals(unsigned char row[],
		 int begin,
		 int end,
		 Interval interval_array[],
		 int threshold)
{
  int count;
  int j;

/*  printf("get_intervals: begin = %d, end = %d\n", begin, end);  */

  /* get the set of intervals in this row */
  count = 0;
  j = begin;
  while (1)
    {
      /*
       * advance to the first array element greater than or equal to
       * threshold
       */
      while (j <= end && row[j] < threshold)
	j++;
      
      /* determine whether we have a true beginning of the interval */
      if (j <= end)
	{
	  interval_array[count].begin = j;
/*	  printf("begin is %d, elt is %d\n", j, row[j]); */
	}
      else
	break;
      
      /* determine the end of the interval */
      while (j <= end && row[j] >= threshold)
	j++;
      
      interval_array[count].end = j-1;

      count++;
    }
  return(count);
}     

/*
 * Determine the set of intervals between begin and end in the array row
 * which are below threshold and store the results in interval_array.
 *
 * Inputs:
 *  	row 		- array of bytes to examine
 * 	begin		- beginning of data to examine in row
 * 	end		- end of data to examine in row
 *  	threshold	- the given threshold
 *
 * Outputs:
 * 	the intervals found are stored in interval_array
 *
 * Returns:
 *  	the number of intervals found
 */
int
EG_get_intervals_below(unsigned char row[],
		      int begin,
		      int end,
		      Interval interval_array[],
		      int threshold)
{
  int count;
  int j;

/*  printf("get_intervals: begin = %d, end = %d\n", begin, end);  */

  /* get the set of intervals in this row */
  count = 0;
  j = begin;
  while (1)
    {
      /*
       * advance to the first array element less than threshold
       */
      while (j <= end && row[j] >= threshold)
	j++;
      
      /* determine whether we have a true beginning of the interval */
      if (j <= end)
	{
	  interval_array[count].begin = j;
/*	  printf("begin is %d, elt is %d\n", j, row[j]); */
	}
      else
	break;
      
      /* determine the end of the interval */
      while (j <= end && row[j] < threshold)
	j++;
      
      interval_array[count].end = j-1;

      count++;
    }
  return(count);
}