NetBSD/games/hack/hack.track.c

/*	$NetBSD: hack.track.c,v 1.4 1997/10/19 16:59:11 christos Exp $	*/

/*
 * Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: hack.track.c,v 1.4 1997/10/19 16:59:11 christos Exp $");
#endif				/* not lint */

#include "hack.h"
#include "extern.h"

#define	UTSZ	50

coord           utrack[UTSZ];
int             utcnt = 0;
int             utpnt = 0;

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

/* 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++;
}

coord          *
gettrack(x, y)
	int x, y;
{
	int             i, cnt, dist;
	coord           tc;
	cnt = utcnt;
	for (i = utpnt - 1; cnt--; i--) {
		if (i == -1)
			i = UTSZ - 1;
		tc = utrack[i];
		dist = (x - tc.x) * (x - tc.x) + (y - tc.y) * (y - tc.y);
		if (dist < 3)
			return (dist ? &(utrack[i]) : 0);
	}
	return (0);
}