#define         SHORT           short
#define         TRUE    1
#define         FALSE   0
 
#define MELEMENT        struct Melement
MELEMENT {
    short       x, y;   /* grid coordinates */
    int         value;
    MELEMENT    *next, *prior;  /* next and prior element in row list */
    };

#define NEIGHBOR        struct neighbor
NEIGHBOR {
    double      distance;
    MELEMENT    *Mptr,          /* pointer to data in linked lists of input */
                **searchptr;    /* row search pointer that identified this
                                   neighbor */
    NEIGHBOR    *next;
    };

/* structure for search pointers which access a row list of MELEMENTs */
/* if latitude-longitude, ealive and walive prevent search collisions on a
   circular, doubly-linked list; else, list is linear (NULL terminated) and
   pointers to MELEMENT are set NULL to indicate end of search in a direction */
#define EW              struct ew
EW {
    MELEMENT    *east,  /* next eastward search in this row */
                *west,  /* next westward search in this row */
                *start; /* starting point of east and west search in this row */
    short       ealive, walive; /* used only for latitude-longitude,
                                   TRUE if search is active in this direction */
    EW          *next;
    };
 
#ifdef MAIN
 
struct Cell_head        window ;
CELL                    *cell, *mask;
double                  *rowlook, *collook,
			*lat_diff,	/* distances between latitudes */
                        ew2;

short                   ll;     /* TRUE if latitude-longitude projection */

/* function pointers for LL function substitutes */

int first_west(EW *, SHORT);
int first_west_LL(EW *, SHORT);
int         (*init_row_search) (EW *, SHORT);  /* function pointer */
 
int completed_row(EW *);
int completed_row_LL(EW *);
 /* function pointer */
int         (*comp_row_search) (EW *);

int find_neighbors(EW *, NEIGHBOR *, SHORT, SHORT, int, SHORT *);
int find_neighbors_LL(EW *, NEIGHBOR *, SHORT, SHORT, int, SHORT *);
 /* function pointer */
int         (*locate_neighbors) (EW *, NEIGHBOR *, SHORT, SHORT, int, SHORT *);

int exhaust_search(EW *, NEIGHBOR *, SHORT, SHORT);
int exhaust_search_LL(EW *, NEIGHBOR *, SHORT, SHORT);
/* function pointer */
int         (*exhaust_row) (EW *, NEIGHBOR *, SHORT, SHORT);

double offset_distance(SHORT);
double offset_distance_LL(SHORT);
double      (*check_offset) (SHORT);  /* function pointer */

#endif

/* dist.c */
int G_begin_geodesic_distance_l(short, double, double);
double LL_set_geodesic_distance_lat(double);
double set_sdlmr(double);
int LL_set_geodesic_distance(double *, int, int);
double LL_geodesic_distance(double);
int free_dist_params(void);
/* ll.c */
int extend_west(EW *);
int extend_east(EW *);
double distance_LL(SHORT, SHORT, MELEMENT *);
int LL_lookup_tables(SHORT, SHORT);
/* main.c */
int lookup_and_function_ptrs(SHORT, SHORT);
int interpolate(MELEMENT [], SHORT, SHORT, SHORT, int, int, int);
int make_neighbors_list(EW *, EW *, EW *, SHORT, SHORT, NEIGHBOR *, int);
int search(EW **, NEIGHBOR *, SHORT, SHORT, int, SHORT *, EW *, SHORT);
int exhaust(EW **, NEIGHBOR *, SHORT, SHORT);
EW *next_row(EW *, EW *, SHORT *, SHORT);
double triangulate(MELEMENT *, SHORT, SHORT);
int add_neighbor(MELEMENT **, NEIGHBOR *, double, int);
int replace_neighbor(MELEMENT **, NEIGHBOR *, double);
int sort_neighbors(NEIGHBOR *, double);
int free_row_lists(MELEMENT *, SHORT);
MELEMENT *row_lists(SHORT, SHORT, SHORT *, int *, int, CELL *);
int lookup_tables(SHORT, SHORT);