NetBSD/games/backgammon/common_source/allow.c

114 lines
3.1 KiB
C

/* $NetBSD: allow.c,v 1.8 2012/10/13 19:19:38 dholland Exp $ */
/*
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)allow.c 8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: allow.c,v 1.8 2012/10/13 19:19:38 dholland Exp $");
#endif
#endif /* not lint */
#include "back.h"
int
movallow(struct move *mm)
{
int i, m, iold;
int r;
if (mm->d0)
mswap(mm);
m = (mm->D0 == mm->D1 ? 4 : 2);
for (i = 0; i < 4; i++)
mm->p[i] = bar;
i = iold = 0;
while (i < m) {
if (*offptr == 15)
break;
mm->h[i] = 0;
if (board[bar]) {
if (i == 1 || m == 4)
mm->g[i] = bar + cturn * mm->D1;
else
mm->g[i] = bar + cturn * mm->D0;
if ((r = makmove(mm, i)) != 0) {
if (mm->d0 || m == 4)
break;
mswap(mm);
movback(mm, i);
if (i > iold)
iold = i;
for (i = 0; i < 4; i++)
mm->p[i] = bar;
i = 0;
} else
i++;
continue;
}
if ((mm->p[i] += cturn) == home) {
if (i > iold)
iold = i;
if (m == 2 && i) {
movback(mm, i);
mm->p[i--] = bar;
if (mm->p[i] != bar)
continue;
else
break;
}
if (mm->d0 || m == 4)
break;
mswap(mm);
movback(mm, i);
for (i = 0; i < 4; i++)
mm->p[i] = bar;
i = 0;
continue;
}
if (i == 1 || m == 4)
mm->g[i] = mm->p[i] + cturn * mm->D1;
else
mm->g[i] = mm->p[i] + cturn * mm->D0;
if (mm->g[i] * cturn > home) {
if (*offptr >= 0)
mm->g[i] = home;
else
continue;
}
if (board[mm->p[i]] * cturn > 0 && (r = makmove(mm, i)) == 0)
i++;
}
movback(mm, i);
return (iold > i ? iold : i);
}