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