robots/rnd_pos.c

   1 /*
   2  * Copyright (c) 1980 Regents of the University of California.
   3  * 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
  34 #ifndef lint
  35 static char sccsid[] = "@(#)rnd_pos.c   5.4 (Berkeley) 6/1/90";
  36 #endif /* not lint */
  37
  38 # include       "robots.h"
  39
  40 # define        IS_SAME(p,y,x)  ((p).y != -1 && (p).y == y && (p).x == x)
  41
  42 /*
  43  * rnd_pos:
  44  *      Pick a random, unoccupied position
  45  */
  46 COORD *
  47 rnd_pos()
  48 {
  49         static COORD    pos;
  50         static int      call = 0;
  51         register int    i = 0;
  52
  53         do {
  54                 pos.y = rnd(Y_FIELDSIZE - 1) + 1;
  55                 pos.x = rnd(X_FIELDSIZE - 1) + 1;
  56                 refresh();
  57         } while (Field[pos.y][pos.x] != 0);
  58         call++;
  59         return &pos;
  60 }
  61
  62 rnd(range)
  63 int     range;
  64 {
  65         unsigned int    rand();
  66
  67         return rand() % range;
  68 }