games/robots/rnd_pos.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)rnd_pos.c        8.1 (Berkeley) 5/31/93
  34  * $FreeBSD: src/games/robots/rnd_pos.c,v 1.5 1999/11/30 03:49:20 billf Exp $
  35  * $DragonFly: src/games/robots/rnd_pos.c,v 1.3 2006/08/27 21:45:07 pavalos Exp $
  36  */
  37
  38 # include       "robots.h"
  39
  40 # define        IS_SAME(p,y,x)  ((p).y != -1 && (p).y == y && (p).x == x)
  41
  42 static int      rnd(int);
  43
  44 /*
  45  * rnd_pos:
  46  *      Pick a random, unoccupied position
  47  */
  48 COORD *
  49 rnd_pos(void)
  50 {
  51         static COORD    pos;
  52         static int      call = 0;
  53
  54         do {
  55                 pos.y = rnd(Y_FIELDSIZE - 1) + 1;
  56                 pos.x = rnd(X_FIELDSIZE - 1) + 1;
  57                 refresh();
  58         } while (Field[pos.y][pos.x] != 0);
  59         call++;
  60         return &pos;
  61 }
  62
  63 static int
  64 rnd(int range)
  65 {
  66         return random() % range;
  67 }