1 /* 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. 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 #if 0 36 static char sccsid[] = "@(#)allow.c 8.1 (Berkeley) 5/31/93"; 37 #endif 38 static const char rcsid[] = 39 "$FreeBSD: src/games/backgammon/common_source/allow.c,v 1.4 1999/11/30 03:48:24 billf Exp $"; 40 #endif /* not lint */ 41 42 #include "back.h" 43 44 movallow () { 45 46 int i, m, iold; 47 int r; 48 49 if (d0) 50 swap; 51 m = (D0 == D1? 4: 2); 52 for (i = 0; i < 4; i++) 53 p[i] = bar; 54 i = iold = 0; 55 while (i < m) { 56 if (*offptr == 15) 57 break; 58 h[i] = 0; 59 if (board[bar]) { 60 if (i == 1 || m == 4) 61 g[i] = bar+cturn*D1; 62 else 63 g[i] = bar+cturn*D0; 64 if (r = makmove(i)) { 65 if (d0 || m == 4) 66 break; 67 swap; 68 movback (i); 69 if (i > iold) 70 iold = i; 71 for (i = 0; i < 4; i++) 72 p[i] = bar; 73 i = 0; 74 } else 75 i++; 76 continue; 77 } 78 if ((p[i] += cturn) == home) { 79 if (i > iold) 80 iold = i; 81 if (m == 2 && i) { 82 movback(i); 83 p[i--] = bar; 84 if (p[i] != bar) 85 continue; 86 else 87 break; 88 } 89 if (d0 || m == 4) 90 break; 91 swap; 92 movback (i); 93 for (i = 0; i < 4; i++) 94 p[i] = bar; 95 i = 0; 96 continue; 97 } 98 if (i == 1 || m == 4) 99 g[i] = p[i]+cturn*D1; 100 else 101 g[i] = p[i]+cturn*D0; 102 if (g[i]*cturn > home) { 103 if (*offptr >= 0) 104 g[i] = home; 105 else 106 continue; 107 } 108 if (board[p[i]]*cturn > 0 && (r = makmove(i)) == 0) 109 i++; 110 } 111 movback (i); 112 return (iold > i? iold: i); 113 } 114