/*	SCCS Id: @(#)track.c	3.3	87/08/08	*/
/* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
/* NetHack may be freely redistributed.  See license for details. */
/* track.c - version 1.0.2 */

#include "hack.h"

#define UTSZ	50

STATIC_VAR NEARDATA int utcnt, utpnt;
STATIC_VAR NEARDATA coord utrack[UTSZ];

#ifdef OVLB

void
initrack()
{
	utcnt = utpnt = 0;
}

#endif /* OVLB */
#ifdef OVL1

/* add to track */
void
settrack()
{
	if(utcnt < UTSZ) utcnt++;
	if(utpnt == UTSZ) utpnt = 0;
	utrack[utpnt].x = u.ux;
	utrack[utpnt].y = u.uy;
	utpnt++;
}

#endif /* OVL1 */
#ifdef OVL0

coord *
gettrack(x, y)
register int x, y;
{
    register int cnt, ndist;
    register coord *tc;
    cnt = utcnt;
    for(tc = &utrack[utpnt]; cnt--; ){
	if(tc == utrack) tc = &utrack[UTSZ-1];
	else tc--;
	ndist = distmin(x,y,tc->x,tc->y);

	/* if far away, skip track entries til we're closer */
	if(ndist > 2) {
	    ndist -= 2; /* be careful due to extra decrement at top of loop */
	    cnt -= ndist;
	    if(cnt <= 0)
		return (coord *) 0; /* too far away, no matches possible */
	    if(tc < &utrack[ndist])
		tc += (UTSZ-ndist);
	    else
		tc -= ndist;
	} else if(ndist <= 1)
	    return(ndist ? tc : 0);
    }
    return (coord *)0;
}

#endif /* OVL0 */

/*track.c*/