hack/hack.track.c

   1 /*      $NetBSD: hack.track.c,v 1.4 1997/10/19 16:59:11 christos Exp $  */
   2
   3 /*
   4  * Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985.
   5  */
   6
   7 #include <sys/cdefs.h>
   8 #ifndef lint
   9 __RCSID("$NetBSD: hack.track.c,v 1.4 1997/10/19 16:59:11 christos Exp $");
  10 #endif                          /* not lint */
  11
  12 #include "hack.h"
  13 #include "extern.h"
  14
  15 #define UTSZ    50
  16
  17 coord           utrack[UTSZ];
  18 int             utcnt = 0;
  19 int             utpnt = 0;
  20
  21 void
  22 initrack()
  23 {
  24         utcnt = utpnt = 0;
  25 }
  26
  27 /* add to track */
  28 void
  29 settrack()
  30 {
  31         if (utcnt < UTSZ)
  32                 utcnt++;
  33         if (utpnt == UTSZ)
  34                 utpnt = 0;
  35         utrack[utpnt].x = u.ux;
  36         utrack[utpnt].y = u.uy;
  37         utpnt++;
  38 }
  39
  40 coord          *
  41 gettrack(x, y)
  42         int x, y;
  43 {
  44         int             i, cnt, dist;
  45         coord           tc;
  46         cnt = utcnt;
  47         for (i = utpnt - 1; cnt--; i--) {
  48                 if (i == -1)
  49                         i = UTSZ - 1;
  50                 tc = utrack[i];
  51                 dist = (x - tc.x) * (x - tc.x) + (y - tc.y) * (y - tc.y);
  52                 if (dist < 3)
  53                         return (dist ? &(utrack[i]) : 0);
  54         }
  55         return (0);
  56 }