1    | /*	SCCS Id: @(#)track.c	3.3	87/08/08	*/
2    | /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
3    | /* NetHack may be freely redistributed.  See license for details. */
4    | /* track.c - version 1.0.2 */
5    | 
6    | #include "hack.h"
7    | 
8    | #define UTSZ	50
9    | 
10   | STATIC_VAR NEARDATA int utcnt, utpnt;
11   | STATIC_VAR NEARDATA coord utrack[UTSZ];
12   | 
13   | #ifdef OVLB
14   | 
15   | void
16   | initrack()
17   | {
18   | 	utcnt = utpnt = 0;
19   | }
20   | 
21   | #endif /* OVLB */
22   | #ifdef OVL1
23   | 
24   | /* add to track */
25   | void
26   | settrack()
27   | {
28   | 	if(utcnt < UTSZ) utcnt++;
29   | 	if(utpnt == UTSZ) utpnt = 0;
30   | 	utrack[utpnt].x = u.ux;
31   | 	utrack[utpnt].y = u.uy;
32   | 	utpnt++;
33   | }
34   | 
35   | #endif /* OVL1 */
36   | #ifdef OVL0
37   | 
38   | coord *
39   | gettrack(x, y)
40   | register int x, y;
41   | {
42   |     register int cnt, ndist;
43   |     register coord *tc;
44   |     cnt = utcnt;
45   |     for(tc = &utrack[utpnt]; cnt--; ){
46   | 	if(tc == utrack) tc = &utrack[UTSZ-1];
47   | 	else tc--;
48   | 	ndist = distmin(x,y,tc->x,tc->y);
49   | 
50   | 	/* if far away, skip track entries til we're closer */
51   | 	if(ndist > 2) {
52   | 	    ndist -= 2; /* be careful due to extra decrement at top of loop */
53   | 	    cnt -= ndist;
54   | 	    if(cnt <= 0)
55   | 		return (coord *) 0; /* too far away, no matches possible */
56   | 	    if(tc < &utrack[ndist])
57   | 		tc += (UTSZ-ndist);
58   | 	    else
59   | 		tc -= ndist;
60   | 	} else if(ndist <= 1)
61   | 	    return(ndist ? tc : 0);
62   |     }
63   |     return (coord *)0;
64   | }
65   | 
66   | #endif /* OVL0 */
67   | 
68   | /*track.c*/