hack/hack.track.c

   1 /*
   2  * Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985.
   3  */
   4
   5 #ifndef lint
   6 static char rcsid[] = "$NetBSD: hack.track.c,v 1.3 1995/03/23 08:31:42 cgd Exp $";
   7 #endif /* not lint */
   8
   9 #include "hack.h"
  10
  11 #define UTSZ    50
  12
  13 coord utrack[UTSZ];
  14 int utcnt = 0;
  15 int utpnt = 0;
  16
  17 initrack(){
  18         utcnt = utpnt = 0;
  19 }
  20
  21 /* add to track */
  22 settrack(){
  23         if(utcnt < UTSZ) utcnt++;
  24         if(utpnt == UTSZ) utpnt = 0;
  25         utrack[utpnt].x = u.ux;
  26         utrack[utpnt].y = u.uy;
  27         utpnt++;
  28 }
  29
  30 coord *
  31 gettrack(x,y) register x,y; {
  32 register int i,cnt,dist;
  33 coord tc;
  34         cnt = utcnt;
  35         for(i = utpnt-1; cnt--; i--){
  36                 if(i == -1) i = UTSZ-1;
  37                 tc = utrack[i];
  38                 dist = (x-tc.x)*(x-tc.x) + (y-tc.y)*(y-tc.y);
  39                 if(dist < 3)
  40                         return(dist ? &(utrack[i]) : 0);
  41         }
  42         return(0);
  43 }