/****************************************************************
 * I_cluster_point (C,x)
 *     struct Cluster *C;
 *     CELL *x;
 *
 * adds the point x to the list of data points to be "clustered"
 *
 * returns
 *   0  ok
 *  -1  out of memory, point not added
 *   1  all values are zero, point not added
 *
 * the dimension of x must agree with the number of bands specified
 * in the initializing call to I_cluster_begin()
 *
 * note: if all values in x are zero, the point is rejected
 ***************************************************************/

#include <grass/imagery.h>
static int extend(struct Cluster *,int);
static int all_zero(struct Cluster *,int);

int I_cluster_point( struct Cluster *C, CELL *x)
{
    int band;

/* reject points which contain nulls in one of the bands */
    for (band = 0; band < C->nbands; band++)
	if (G_is_c_null_value(&x[band])) return 1; /* fixed 11/99 Agus Carr */
/*
    if (band >= C->nbands)
	return 1;
*/

/* extend the arrays for each band, if necessary */
    if(!extend(C,1))
	return -1;

/* add the point to the points arrays */
    for (band = 0; band < C->nbands; band++)
    {
	register double z;

 /*       if(G_is_c_null_value(&x[band])) continue;*/
	z = C->points[band][C->npoints] = x[band];
	C->band_sum[band]  += z;
	C->band_sum2[band] += z*z;
    }
    C->npoints++;
    return 0;
}

int I_cluster_begin_point_set (struct Cluster *C, int n)
{
    return extend(C,n) ? 0 : -1;
}

int I_cluster_point_part (
    struct Cluster *C,register CELL x,int band, int n)
{
    CELL tmp=x;
    if(G_is_c_null_value(&tmp)) return 1;
    C->points[band][C->npoints+n] = x;
    C->band_sum[band]  += (double) x;
    C->band_sum2[band] += (double) x*x;

    return 0;
}

int I_cluster_end_point_set (
    struct Cluster *C, int n)
{
    int band;
    int cur,next;

    cur = C->npoints;
    n += C->npoints;
    for (next = cur; next < n; next++)
    {
	if (!all_zero (C, next))
	{
	    if (cur != next)
		for (band = 0; band < C->nbands; band++)
		    C->points[band][cur] = C->points[band][next] ;
	    cur++;
	}
    }
    return C->npoints = cur;
}

static int all_zero(struct Cluster *C, int i)
{
    int band;

    for (band = 0; band < C->nbands; band++)
	if (C->points[band][i])
	    return 0;
    return 1;
}

static int extend(struct Cluster *C, int n)
{
    int band;
    while ((C->npoints+n) > C->np)
    {
	C->np += 128;
	for (band = 0; band < C->nbands; band++)
	{
	    C->points[band] = (CELL *) I_realloc (C->points[band], C->np * sizeof (CELL)) ;
	    if (C->points[band] == NULL)
		return 0;
	}
    }
    return 1;
}