1 /* $OpenBSD: allow.c,v 1.6 2015/11/30 08:19:25 tb 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 "back.h" 33 34 int 35 movallow(void) 36 { 37 int i, m, iold, r; 38 39 if (d0) 40 swap; 41 m = (D0 == D1 ? 4 : 2); 42 for (i = 0; i < 4; i++) 43 p[i] = bar; 44 i = iold = 0; 45 while (i < m) { 46 if (*offptr == 15) 47 break; 48 h[i] = 0; 49 if (board[bar]) { 50 if (i == 1 || m == 4) 51 g[i] = bar + cturn * D1; 52 else 53 g[i] = bar + cturn * D0; 54 if ((r = makmove(i))) { 55 if (d0 || m == 4) 56 break; 57 swap; 58 movback(i); 59 if (i > iold) 60 iold = i; 61 for (i = 0; i < 4; i++) 62 p[i] = bar; 63 i = 0; 64 } else 65 i++; 66 continue; 67 } 68 if ((p[i] += cturn) == home) { 69 if (i > iold) 70 iold = i; 71 if (m == 2 && i) { 72 movback(i); 73 p[i--] = bar; 74 if (p[i] != bar) 75 continue; 76 else 77 break; 78 } 79 if (d0 || m == 4) 80 break; 81 swap; 82 movback(i); 83 for (i = 0; i < 4; i++) 84 p[i] = bar; 85 i = 0; 86 continue; 87 } 88 if (i == 1 || m == 4) 89 g[i] = p[i] + cturn * D1; 90 else 91 g[i] = p[i] + cturn * D0; 92 if (g[i] * cturn > home) { 93 if (*offptr >= 0) 94 g[i] = home; 95 else 96 continue; 97 } 98 if (board[p[i]] * cturn > 0 && (r = makmove(i)) == 0) 99 i++; 100 } 101 movback(i); 102 return (iold > i ? iold : i); 103 } 104