xref: /netbsd-src/games/backgammon/common_source/one.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: one.c,v 1.6 2005/07/01 01:12:39 jmc 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[] = "@(#)one.c	8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: one.c,v 1.6 2005/07/01 01:12:39 jmc Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include "back.h"
42 
43 int
44 makmove(int i)
45 {
46 	int     n, d;
47 	int     max;
48 
49 	d = d0;
50 	n = abs(g[i] - p[i]);
51 	max = (*offptr < 0 ? 7 : last());
52 	if (board[p[i]] * cturn <= 0)
53 		return (checkd(d) + 2);
54 	if (g[i] != home && board[g[i]] * cturn < -1)
55 		return (checkd(d) + 3);
56 	if (i || D0 == D1) {
57 		if (n == max ? D1 < n : D1 != n)
58 			return (checkd(d) + 1);
59 	} else {
60 		if (n == max ? D0 < n && D1 < n : D0 != n && D1 != n)
61 			return (checkd(d) + 1);
62 		if (n == max ? D0 < n : D0 != n) {
63 			if (d0)
64 				return (checkd(d) + 1);
65 			swap;
66 		}
67 	}
68 	if (g[i] == home && *offptr < 0)
69 		return (checkd(d) + 4);
70 	h[i] = 0;
71 	board[p[i]] -= cturn;
72 	if (g[i] != home) {
73 		if (board[g[i]] == -cturn) {
74 			board[home] -= cturn;
75 			board[g[i]] = 0;
76 			h[i] = 1;
77 			if (abs(bar - g[i]) < 7) {
78 				(*inopp)--;
79 				if (*offopp >= 0)
80 					*offopp -= 15;
81 			}
82 		}
83 		board[g[i]] += cturn;
84 		if (abs(home - g[i]) < 7 && abs(home - p[i]) > 6) {
85 			(*inptr)++;
86 			if (*inptr + *offptr == 0)
87 				*offptr += 15;
88 		}
89 	} else {
90 		(*offptr)++;
91 		(*inptr)--;
92 	}
93 	return (0);
94 }
95 
96 void
97 moverr(int i)
98 {
99 	int     j;
100 
101 	if (tflag)
102 		curmove(20, 0);
103 	else
104 		writec('\n');
105 	writel("Error:  ");
106 	for (j = 0; j <= i; j++) {
107 		wrint(p[j]);
108 		writec('-');
109 		wrint(g[j]);
110 		if (j < i)
111 			writec(',');
112 	}
113 	writel("... ");
114 	movback(i);
115 }
116 
117 
118 int
119 checkd(int d)
120 {
121 	if (d0 != d)
122 		swap;
123 	return (0);
124 }
125 
126 int
127 last(void)
128 {
129 	int     i;
130 
131 	for (i = home - 6 * cturn; i != home; i += cturn)
132 		if (board[i] * cturn > 0)
133 			return (abs(home - i));
134 	return (-1);
135 }
136 
137 void
138 movback(int i)
139 {
140 	int     j;
141 
142 	for (j = i - 1; j >= 0; j--)
143 		backone(j);
144 }
145 
146 void
147 backone(int i)
148 {
149 	board[p[i]] += cturn;
150 	if (g[i] != home) {
151 		board[g[i]] -= cturn;
152 		if (abs(g[i] - home) < 7 && abs(p[i] - home) > 6) {
153 			(*inptr)--;
154 			if (*inptr + *offptr < 15 && *offptr >= 0)
155 				*offptr -= 15;
156 		}
157 	} else {
158 		(*offptr)--;
159 		(*inptr)++;
160 	}
161 	if (h[i]) {
162 		board[home] += cturn;
163 		board[g[i]] = -cturn;
164 		if (abs(bar - g[i]) < 7) {
165 			(*inopp)++;
166 			if (*inopp + *offopp == 0)
167 				*offopp += 15;
168 		}
169 	}
170 }
171