1: /*      $NetBSD: hack.track.c,v 1.5 2003/04/02 18:36:41 jsm Exp $    */
    2: 
    3: /*
    4:  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
    5:  * Amsterdam
    6:  * All rights reserved.
    7:  *
    8:  * Redistribution and use in source and binary forms, with or without
    9:  * modification, are permitted provided that the following conditions are
   10:  * met:
   11:  *
   12:  * - Redistributions of source code must retain the above copyright notice,
   13:  * this list of conditions and the following disclaimer.
   14:  *
   15:  * - Redistributions in binary form must reproduce the above copyright
   16:  * notice, this list of conditions and the following disclaimer in the
   17:  * documentation and/or other materials provided with the distribution.
   18:  *
   19:  * - Neither the name of the Stichting Centrum voor Wiskunde en
   20:  * Informatica, nor the names of its contributors may be used to endorse or
   21:  * promote products derived from this software without specific prior
   22:  * written permission.
   23:  *
   24:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
   25:  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   26:  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   27:  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   28:  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   29:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   30:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   31:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   32:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   33:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   34:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   35:  */
   36: 
   37: /*
   38:  * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
   39:  * All rights reserved.
   40:  *
   41:  * Redistribution and use in source and binary forms, with or without
   42:  * modification, are permitted provided that the following conditions
   43:  * are met:
   44:  * 1. Redistributions of source code must retain the above copyright
   45:  *    notice, this list of conditions and the following disclaimer.
   46:  * 2. Redistributions in binary form must reproduce the above copyright
   47:  *    notice, this list of conditions and the following disclaimer in the
   48:  *    documentation and/or other materials provided with the distribution.
   49:  * 3. The name of the author may not be used to endorse or promote products
   50:  *    derived from this software without specific prior written permission.
   51:  *
   52:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
   53:  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
   54:  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
   55:  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   56:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   57:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   58:  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   59:  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   60:  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   61:  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   62:  */
   63: 
   64: #include <sys/cdefs.h>
   65: #ifndef lint
   66: __RCSID("$NetBSD: hack.track.c,v 1.5 2003/04/02 18:36:41 jsm Exp $");
   67: #endif                          /* not lint */
   68: 
   69: #include "hack.h"
   70: #include "extern.h"
   71: 
   72: #define UTSZ    50
   73: 
   74: coord           utrack[UTSZ];
   75: int             utcnt = 0;
   76: int             utpnt = 0;
   77: 
   78: void
   79: initrack()
   80: {
   81:         utcnt = utpnt = 0;
   82: }
   83: 
   84: /* add to track */
   85: void
   86: settrack()
   87: {
   88:         if (utcnt < UTSZ)
   89:                 utcnt++;
   90:         if (utpnt == UTSZ)
   91:                 utpnt = 0;
   92:         utrack[utpnt].x = u.ux;
   93:         utrack[utpnt].y = u.uy;
   94:         utpnt++;
   95: }
   96: 
   97: coord          *
   98: gettrack(x, y)
   99:         int x, y;
  100: {
  101:         int             i, cnt, dist;
  102:         coord           tc;
  103:         cnt = utcnt;
  104:         for (i = utpnt - 1; cnt--; i--) {
  105:                 if (i == -1)
  106:                         i = UTSZ - 1;
  107:                 tc = utrack[i];
  108:                 dist = (x - tc.x) * (x - tc.x) + (y - tc.y) * (y - tc.y);
  109:                 if (dist < 3)
  110:                         return (dist ? &(utrack[i]) : 0);
  111:         }
  112:         return (0);
  113: }