xref: /netbsd-src/games/gomoku/bdinit.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: bdinit.c,v 1.9 2012/10/13 20:57:35 dholland Exp $	*/
2 
3 /*
4  * Copyright (c) 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Ralph Campbell.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "from: @(#)bdinit.c	8.2 (Berkeley) 5/3/95";
39 #else
40 __RCSID("$NetBSD: bdinit.c,v 1.9 2012/10/13 20:57:35 dholland Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <string.h>
45 #include "gomoku.h"
46 
47 static void init_overlap(void);
48 
49 void
50 bdinit(struct spotstr *bp)
51 {
52 	int i, j, r;
53 	struct spotstr *sp;
54 	struct combostr *cbp;
55 
56 	movenum = 1;
57 
58 	/* mark the borders as such */
59 	sp = bp;
60 	for (i = BSZ2; --i >= 0; sp++) {
61 		sp->s_occ = BORDER;		/* top border */
62 		sp->s_flags = BFLAGALL;
63 	}
64 
65 	/* fill entire board with EMPTY spots */
66 	memset(frames, 0, sizeof(frames));
67 	cbp = frames;
68 	for (j = 0; ++j < BSZ1; sp++) {			/* for each row */
69 		for (i = 0; ++i < BSZ1; sp++) {		/* for each column */
70 			sp->s_occ = EMPTY;
71 			sp->s_flags = 0;
72 			sp->s_wval = 0;
73 			if (j < 5) {
74 				/* directions 1, 2, 3 are blocked */
75 				sp->s_flags |= (BFLAG << 1) | (BFLAG << 2) |
76 					(BFLAG << 3);
77 				sp->s_fval[BLACK][1].s = MAXCOMBO;
78 				sp->s_fval[BLACK][2].s = MAXCOMBO;
79 				sp->s_fval[BLACK][3].s = MAXCOMBO;
80 				sp->s_fval[WHITE][1].s = MAXCOMBO;
81 				sp->s_fval[WHITE][2].s = MAXCOMBO;
82 				sp->s_fval[WHITE][3].s = MAXCOMBO;
83 			} else if (j == 5) {
84 				/* five spaces, blocked on one side */
85 				sp->s_fval[BLACK][1].s = 0x500;
86 				sp->s_fval[BLACK][2].s = 0x500;
87 				sp->s_fval[BLACK][3].s = 0x500;
88 				sp->s_fval[WHITE][1].s = 0x500;
89 				sp->s_fval[WHITE][2].s = 0x500;
90 				sp->s_fval[WHITE][3].s = 0x500;
91 			} else {
92 				/* six spaces, not blocked */
93 				sp->s_fval[BLACK][1].s = 0x401;
94 				sp->s_fval[BLACK][2].s = 0x401;
95 				sp->s_fval[BLACK][3].s = 0x401;
96 				sp->s_fval[WHITE][1].s = 0x401;
97 				sp->s_fval[WHITE][2].s = 0x401;
98 				sp->s_fval[WHITE][3].s = 0x401;
99 			}
100 			if (i > (BSZ - 4)) {
101 				/* directions 0, 1 are blocked */
102 				sp->s_flags |= BFLAG | (BFLAG << 1);
103 				sp->s_fval[BLACK][0].s = MAXCOMBO;
104 				sp->s_fval[BLACK][1].s = MAXCOMBO;
105 				sp->s_fval[WHITE][0].s = MAXCOMBO;
106 				sp->s_fval[WHITE][1].s = MAXCOMBO;
107 			} else if (i == (BSZ - 4)) {
108 				sp->s_fval[BLACK][0].s = 0x500;
109 				sp->s_fval[WHITE][0].s = 0x500;
110 				/* if direction 1 is not blocked */
111 				if (!(sp->s_flags & (BFLAG << 1))) {
112 					sp->s_fval[BLACK][1].s = 0x500;
113 					sp->s_fval[WHITE][1].s = 0x500;
114 				}
115 			} else {
116 				sp->s_fval[BLACK][0].s = 0x401;
117 				sp->s_fval[WHITE][0].s = 0x401;
118 				if (i < 5) {
119 					/* direction 3 is blocked */
120 					sp->s_flags |= (BFLAG << 3);
121 					sp->s_fval[BLACK][3].s = MAXCOMBO;
122 					sp->s_fval[WHITE][3].s = MAXCOMBO;
123 				} else if (i == 5 &&
124 				    !(sp->s_flags & (BFLAG << 3))) {
125 					sp->s_fval[BLACK][3].s = 0x500;
126 					sp->s_fval[WHITE][3].s = 0x500;
127 				}
128 			}
129 			/*
130 			 * Allocate a frame structure for non blocked frames.
131 			 */
132 			for (r = 4; --r >= 0; ) {
133 				if (sp->s_flags & (BFLAG << r))
134 					continue;
135 				cbp->c_combo.s = sp->s_fval[BLACK][r].s;
136 				cbp->c_vertex = sp - board;
137 				cbp->c_nframes = 1;
138 				cbp->c_dir = r;
139 				sp->s_frame[r] = cbp;
140 				cbp++;
141 			}
142 		}
143 		sp->s_occ = BORDER;		/* left & right border */
144 		sp->s_flags = BFLAGALL;
145 	}
146 
147 	/* mark the borders as such */
148 	for (i = BSZ1; --i >= 0; sp++) {
149 		sp->s_occ = BORDER;		/* bottom border */
150 		sp->s_flags = BFLAGALL;
151 	}
152 
153 	sortframes[BLACK] = (struct combostr *)0;
154 	sortframes[WHITE] = (struct combostr *)0;
155 	init_overlap();
156 }
157 
158 /*
159  * Initialize the overlap array.
160  * Each entry in the array is a bit mask with eight bits corresponding
161  * to whether frame B overlaps frame A (as indexed by overlap[A * FAREA + B]).
162  * The eight bits coorespond to whether A and B are open ended (length 6) or
163  * closed (length 5).
164  *	0	A closed and B closed
165  *	1	A closed and B open
166  *	2	A open and B closed
167  *	3	A open and B open
168  *	4	A closed and B closed and overlaps in more than one spot
169  *	5	A closed and B open and overlaps in more than one spot
170  *	6	A open and B closed and overlaps in more than one spot
171  *	7	A open and B open and overlaps in more than one spot
172  * As pieces are played, it can make frames not overlap if there are no
173  * common open spaces shared between the two frames.
174  */
175 static void
176 init_overlap(void)
177 {
178 	struct spotstr *sp1, *sp2;
179 	struct combostr *cbp;
180 	unsigned frameix;
181 	int i, f, r, n, d1, d2;
182 	int mask, bmask, vertex, s;
183 	u_char *str;
184 	short *ip;
185 
186 	memset(overlap, 0, sizeof(overlap));
187 	memset(intersect, 0, sizeof(intersect));
188 	str = &overlap[FAREA * FAREA];
189 	ip = &intersect[FAREA * FAREA];
190 	for (frameix = FAREA; frameix-- > 0; ) {	/* each frame */
191 	    cbp = &frames[frameix];
192 	    str -= FAREA;
193 	    ip -= FAREA;
194 	    sp1 = &board[vertex = cbp->c_vertex];
195 	    d1 = dd[r = cbp->c_dir];
196 	    /*
197 	     * s = 5 if closed, 6 if open.
198 	     * At this point black & white are the same.
199 	     */
200 	    s = 5 + sp1->s_fval[BLACK][r].c.b;
201 	    /* for each spot in frame A */
202 	    for (i = 0; i < s; i++, sp1 += d1, vertex += d1) {
203 		/* the sixth spot in frame A only overlaps if it is open */
204 		mask = (i == 5) ? 0xC : 0xF;
205 		/* for each direction */
206 		for (r = 4; --r >= 0; ) {
207 		    bmask = BFLAG << r;
208 		    sp2 = sp1;
209 		    d2 = dd[r];
210 		    /* for each frame that intersects at spot sp1 */
211 		    for (f = 0; f < 6; f++, sp2 -= d2) {
212 			if (sp2->s_occ == BORDER)
213 			    break;
214 			if (sp2->s_flags & bmask)
215 			    continue;
216 			n = sp2->s_frame[r] - frames;
217 			ip[n] = vertex;
218 			str[n] |= (f == 5) ? mask & 0xA : mask;
219 			if (r == cbp->c_dir) {
220 			    /* compute the multiple spot overlap values */
221 			    switch (i) {
222 			    case 0:	/* sp1 is the first spot in A */
223 				if (f == 4)
224 				    str[n] |= 0xA0;
225 				else if (f != 5)
226 				    str[n] |= 0xF0;
227 				break;
228 			    case 1:	/* sp1 is the second spot in A */
229 				if (f == 5)
230 				    str[n] |= 0xA0;
231 				else
232 				    str[n] |= 0xF0;
233 				break;
234 			    case 4:	/* sp1 is the penultimate spot in A */
235 				if (f == 0)
236 				    str[n] |= 0xC0;
237 				else
238 				    str[n] |= 0xF0;
239 				break;
240 			    case 5:	/* sp1 is the last spot in A */
241 				if (f == 1)
242 				    str[n] |= 0xC0;
243 				else if (f != 0)
244 				    str[n] |= 0xF0;
245 				break;
246 			    default:
247 				str[n] |= 0xF0;
248 			    }
249 			}
250 		    }
251 		}
252 	    }
253 	}
254 }
255