xref: /netbsd/games/backgammon/common_source/one.c (revision ef75ede9)
1 /*	$NetBSD: one.c,v 1.9 2012/10/13 19:19:39 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[] = "@(#)one.c	8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: one.c,v 1.9 2012/10/13 19:19:39 dholland Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include "back.h"
42 
43 static int checkd(struct move *, int);
44 static int last(void);
45 
46 int
makmove(struct move * mm,int i)47 makmove(struct move *mm, int i)
48 {
49 	int     n, d;
50 	int     max;
51 
52 	d = mm->d0;
53 	n = abs(mm->g[i] - mm->p[i]);
54 	max = (*offptr < 0 ? 7 : last());
55 	if (board[mm->p[i]] * cturn <= 0)
56 		return (checkd(mm, d) + 2);
57 	if (mm->g[i] != home && board[mm->g[i]] * cturn < -1)
58 		return (checkd(mm, d) + 3);
59 	if (i || mm->D0 == mm->D1) {
60 		if (n == max ? mm->D1 < n : mm->D1 != n)
61 			return (checkd(mm, d) + 1);
62 	} else {
63 		if (n == max ? mm->D0 < n && mm->D1 < n : mm->D0 != n && mm->D1 != n)
64 			return (checkd(mm, d) + 1);
65 		if (n == max ? mm->D0 < n : mm->D0 != n) {
66 			if (mm->d0)
67 				return (checkd(mm, d) + 1);
68 			mswap(mm);
69 		}
70 	}
71 	if (mm->g[i] == home && *offptr < 0)
72 		return (checkd(mm, d) + 4);
73 	mm->h[i] = 0;
74 	board[mm->p[i]] -= cturn;
75 	if (mm->g[i] != home) {
76 		if (board[mm->g[i]] == -cturn) {
77 			board[home] -= cturn;
78 			board[mm->g[i]] = 0;
79 			mm->h[i] = 1;
80 			if (abs(bar - mm->g[i]) < 7) {
81 				(*inopp)--;
82 				if (*offopp >= 0)
83 					*offopp -= 15;
84 			}
85 		}
86 		board[mm->g[i]] += cturn;
87 		if (abs(home - mm->g[i]) < 7 && abs(home - mm->p[i]) > 6) {
88 			(*inptr)++;
89 			if (*inptr + *offptr == 0)
90 				*offptr += 15;
91 		}
92 	} else {
93 		(*offptr)++;
94 		(*inptr)--;
95 	}
96 	return (0);
97 }
98 
99 void
moverr(struct move * mm,int i)100 moverr(struct move *mm, int i)
101 {
102 	int     j;
103 
104 	if (tflag)
105 		curmove(20, 0);
106 	else
107 		writec('\n');
108 	writel("Error:  ");
109 	for (j = 0; j <= i; j++) {
110 		wrint(mm->p[j]);
111 		writec('-');
112 		wrint(mm->g[j]);
113 		if (j < i)
114 			writec(',');
115 	}
116 	writel("... ");
117 	movback(mm, i);
118 }
119 
120 
121 static int
checkd(struct move * mm,int d)122 checkd(struct move *mm, int d)
123 {
124 	if (mm->d0 != d)
125 		mswap(mm);
126 	return (0);
127 }
128 
129 static int
last(void)130 last(void)
131 {
132 	int     i;
133 
134 	for (i = home - 6 * cturn; i != home; i += cturn)
135 		if (board[i] * cturn > 0)
136 			return (abs(home - i));
137 	return (-1);
138 }
139 
140 void
movback(struct move * mm,int i)141 movback(struct move *mm, int i)
142 {
143 	int     j;
144 
145 	for (j = i - 1; j >= 0; j--)
146 		backone(mm, j);
147 }
148 
149 void
backone(struct move * mm,int i)150 backone(struct move *mm, int i)
151 {
152 	board[mm->p[i]] += cturn;
153 	if (mm->g[i] != home) {
154 		board[mm->g[i]] -= cturn;
155 		if (abs(mm->g[i] - home) < 7 && abs(mm->p[i] - home) > 6) {
156 			(*inptr)--;
157 			if (*inptr + *offptr < 15 && *offptr >= 0)
158 				*offptr -= 15;
159 		}
160 	} else {
161 		(*offptr)--;
162 		(*inptr)++;
163 	}
164 	if (mm->h[i]) {
165 		board[home] += cturn;
166 		board[mm->g[i]] = -cturn;
167 		if (abs(bar - mm->g[i]) < 7) {
168 			(*inopp)++;
169 			if (*inopp + *offopp == 0)
170 				*offopp += 15;
171 		}
172 	}
173 }
174