#include <stdio.h>
#include <stdlib.h>
#include "delta.h"

/***************************************************************************
GetNeighbors()
	This function creates an array of all the neighbors to a given (x,y)
	pair of points. Value of -9 indicates a neighbor outside the grid.
Arguments: 		struct Basin *basin			pointer to basin parameters
					int x								center x
					int y,                     center y

Return Value:	pointer to array of neighbor (x,y) pairs.
****************************************************************************/
void GetNeighbors(struct Basin *basin, struct Local *local, int x, int y)
{
	int i, j, k;
	struct Local neighbors[8];

	if(y > basin->ymax[0] || x > basin->xmax[0]) {
		printf("\nCoordinates for GetNeighbor lie outside grid:");
		exit(EXIT_FAILURE);
	}
	for(k = 0; k < 8; k++) {
		neighbors[k].x[0] = -9;
		neighbors[k].y[0] = -9;
	}
	for(k = 0, i = (y-1); i < (y+2); i++) {
		for(j = (x-1); j < (x+2); j++, k++, local++) {
			local->y[0] = neighbors[k].y[0] = i;
			local->x[0] = neighbors[k].x[0] = j;
			if(i >= basin->ymax[0] || j >= basin->xmax[0] || i < 0 || j < 0) {
				local->y[0] = neighbors[k].y[0] = -9;
				local->x[0] = neighbors[k].x[0] = -9;
				k--;
				local--;
			}
			if(i == y && j == x) {
				k--;
				local--;
			}
		}
	}
}