games/hack/hack.track.c

   1 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
   2 /* hack.track.c - version 1.0.2 */
   3 /* $FreeBSD: src/games/hack/hack.track.c,v 1.4 1999/11/16 10:26:38 marcel Exp $ */
   4 /* $DragonFly: src/games/hack/hack.track.c,v 1.3 2006/08/21 19:45:32 pavalos Exp $ */
   5
   6 #include "hack.h"
   7
   8 #define UTSZ    50
   9
  10 coord utrack[UTSZ];
  11 int utcnt = 0;
  12 int utpnt = 0;
  13
  14 void
  15 initrack(void)
  16 {
  17         utcnt = utpnt = 0;
  18 }
  19
  20 /* add to track */
  21 void
  22 settrack(void)
  23 {
  24         if (utcnt < UTSZ)
  25                 utcnt++;
  26         if (utpnt == UTSZ)
  27                 utpnt = 0;
  28         utrack[utpnt].x = u.ux;
  29         utrack[utpnt].y = u.uy;
  30         utpnt++;
  31 }
  32
  33 coord *
  34 gettrack(int x, int y)
  35 {
  36         int i, cnt, dst;
  37         coord tc;
  38
  39         cnt = utcnt;
  40         for (i = utpnt - 1; cnt--; i--) {
  41                 if (i == -1)
  42                         i = UTSZ - 1;
  43                 tc = utrack[i];
  44                 dst = (x - tc.x) * (x - tc.x) + (y - tc.y) * (y - tc.y);
  45                 if (dst < 3)
  46                         return (dst ? &(utrack[i]) : 0);
  47         }
  48         return (0);
  49 }