1 /* $NetBSD: allow.c,v 1.8 2012/10/13 19:19:38 dholland Exp $ */ 2 3 /* 4 * Copyright (c) 1980, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)allow.c 8.1 (Berkeley) 5/31/93"; 36 #else 37 __RCSID("$NetBSD: allow.c,v 1.8 2012/10/13 19:19:38 dholland Exp $"); 38 #endif 39 #endif /* not lint */ 40 41 #include "back.h" 42 43 int 44 movallow(struct move *mm) 45 { 46 int i, m, iold; 47 int r; 48 49 if (mm->d0) 50 mswap(mm); 51 m = (mm->D0 == mm->D1 ? 4 : 2); 52 for (i = 0; i < 4; i++) 53 mm->p[i] = bar; 54 i = iold = 0; 55 while (i < m) { 56 if (*offptr == 15) 57 break; 58 mm->h[i] = 0; 59 if (board[bar]) { 60 if (i == 1 || m == 4) 61 mm->g[i] = bar + cturn * mm->D1; 62 else 63 mm->g[i] = bar + cturn * mm->D0; 64 if ((r = makmove(mm, i)) != 0) { 65 if (mm->d0 || m == 4) 66 break; 67 mswap(mm); 68 movback(mm, i); 69 if (i > iold) 70 iold = i; 71 for (i = 0; i < 4; i++) 72 mm->p[i] = bar; 73 i = 0; 74 } else 75 i++; 76 continue; 77 } 78 if ((mm->p[i] += cturn) == home) { 79 if (i > iold) 80 iold = i; 81 if (m == 2 && i) { 82 movback(mm, i); 83 mm->p[i--] = bar; 84 if (mm->p[i] != bar) 85 continue; 86 else 87 break; 88 } 89 if (mm->d0 || m == 4) 90 break; 91 mswap(mm); 92 movback(mm, i); 93 for (i = 0; i < 4; i++) 94 mm->p[i] = bar; 95 i = 0; 96 continue; 97 } 98 if (i == 1 || m == 4) 99 mm->g[i] = mm->p[i] + cturn * mm->D1; 100 else 101 mm->g[i] = mm->p[i] + cturn * mm->D0; 102 if (mm->g[i] * cturn > home) { 103 if (*offptr >= 0) 104 mm->g[i] = home; 105 else 106 continue; 107 } 108 if (board[mm->p[i]] * cturn > 0 && (r = makmove(mm, i)) == 0) 109 i++; 110 } 111 movback(mm, i); 112 return (iold > i ? iold : i); 113 } 114