bdinit.c revision 1.19 1 /* $NetBSD: bdinit.c,v 1.19 2022/05/19 22:29:36 rillig 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 /* from: @(#)bdinit.c 8.2 (Berkeley) 5/3/95 */
37 __RCSID("$NetBSD: bdinit.c,v 1.19 2022/05/19 22:29:36 rillig Exp $");
38
39 #include <string.h>
40 #include "gomoku.h"
41
42 static void init_overlap(void);
43
44 void
45 bdinit(struct spotstr *bp)
46 {
47 struct spotstr *sp;
48 struct combostr *cbp;
49
50 movenum = 1;
51
52 /* mark the borders as such */
53 sp = bp;
54 for (int i = 0; i < 1 + BSZ + 1; i++, sp++) {
55 sp->s_occ = BORDER; /* top border */
56 sp->s_flags = BFLAGALL;
57 }
58
59 /* fill entire board with EMPTY spots */
60 memset(frames, 0, sizeof(frames));
61 cbp = frames;
62 for (int j = 0; ++j < BSZ + 1; sp++) { /* for each row */
63 for (int i = 0; ++i < BSZ + 1; sp++) { /* for each column */
64 sp->s_occ = EMPTY;
65 sp->s_flags = 0;
66 sp->s_wval = 0;
67 if (j < 5) {
68 /* directions 1, 2, 3 are blocked */
69 sp->s_flags |= (BFLAG << 1) | (BFLAG << 2) |
70 (BFLAG << 3);
71 sp->s_fval[BLACK][1].s = MAXCOMBO;
72 sp->s_fval[BLACK][2].s = MAXCOMBO;
73 sp->s_fval[BLACK][3].s = MAXCOMBO;
74 sp->s_fval[WHITE][1].s = MAXCOMBO;
75 sp->s_fval[WHITE][2].s = MAXCOMBO;
76 sp->s_fval[WHITE][3].s = MAXCOMBO;
77 } else if (j == 5) {
78 /* five spaces, blocked on one side */
79 sp->s_fval[BLACK][1].s = 0x500;
80 sp->s_fval[BLACK][2].s = 0x500;
81 sp->s_fval[BLACK][3].s = 0x500;
82 sp->s_fval[WHITE][1].s = 0x500;
83 sp->s_fval[WHITE][2].s = 0x500;
84 sp->s_fval[WHITE][3].s = 0x500;
85 } else {
86 /* six spaces, not blocked */
87 sp->s_fval[BLACK][1].s = 0x401;
88 sp->s_fval[BLACK][2].s = 0x401;
89 sp->s_fval[BLACK][3].s = 0x401;
90 sp->s_fval[WHITE][1].s = 0x401;
91 sp->s_fval[WHITE][2].s = 0x401;
92 sp->s_fval[WHITE][3].s = 0x401;
93 }
94 if (i > (BSZ - 4)) {
95 /* directions 0, 1 are blocked */
96 sp->s_flags |= BFLAG | (BFLAG << 1);
97 sp->s_fval[BLACK][0].s = MAXCOMBO;
98 sp->s_fval[BLACK][1].s = MAXCOMBO;
99 sp->s_fval[WHITE][0].s = MAXCOMBO;
100 sp->s_fval[WHITE][1].s = MAXCOMBO;
101 } else if (i == (BSZ - 4)) {
102 sp->s_fval[BLACK][0].s = 0x500;
103 sp->s_fval[WHITE][0].s = 0x500;
104 /* if direction 1 is not blocked */
105 if ((sp->s_flags & (BFLAG << 1)) == 0) {
106 sp->s_fval[BLACK][1].s = 0x500;
107 sp->s_fval[WHITE][1].s = 0x500;
108 }
109 } else {
110 sp->s_fval[BLACK][0].s = 0x401;
111 sp->s_fval[WHITE][0].s = 0x401;
112 if (i < 5) {
113 /* direction 3 is blocked */
114 sp->s_flags |= (BFLAG << 3);
115 sp->s_fval[BLACK][3].s = MAXCOMBO;
116 sp->s_fval[WHITE][3].s = MAXCOMBO;
117 } else if (i == 5 &&
118 (sp->s_flags & (BFLAG << 3)) == 0) {
119 sp->s_fval[BLACK][3].s = 0x500;
120 sp->s_fval[WHITE][3].s = 0x500;
121 }
122 }
123 /*
124 * Allocate a frame structure for non-blocked frames.
125 */
126 for (int r = 4; --r >= 0; ) {
127 if ((sp->s_flags & (BFLAG << r)) != 0)
128 continue;
129 cbp->c_combo.s = sp->s_fval[BLACK][r].s;
130 cbp->c_vertex = (u_short)(sp - board);
131 cbp->c_nframes = 1;
132 cbp->c_dir = r;
133 sp->s_frame[r] = cbp;
134 cbp++;
135 }
136 }
137 sp->s_occ = BORDER; /* left & right border */
138 sp->s_flags = BFLAGALL;
139 }
140
141 /* mark the borders as such */
142 for (int i = 0; i < BSZ + 1; i++, sp++) {
143 sp->s_occ = BORDER; /* bottom border */
144 sp->s_flags = BFLAGALL;
145 }
146
147 sortframes[BLACK] = NULL;
148 sortframes[WHITE] = NULL;
149 init_overlap();
150 }
151
152 /*
153 * Initialize the overlap array.
154 * Each entry in the array is a bit mask with eight bits corresponding
155 * to whether frame B overlaps frame A (as indexed by overlap[A * FAREA + B]).
156 * The eight bits correspond to whether A and B are open-ended (length 6) or
157 * closed (length 5).
158 * 0 A closed and B closed
159 * 1 A closed and B open
160 * 2 A open and B closed
161 * 3 A open and B open
162 * 4 A closed and B closed and overlaps in more than one spot
163 * 5 A closed and B open and overlaps in more than one spot
164 * 6 A open and B closed and overlaps in more than one spot
165 * 7 A open and B open and overlaps in more than one spot
166 * As pieces are played, it can make frames not overlap if there are no
167 * common open spaces shared between the two frames.
168 */
169 static void
170 init_overlap(void)
171 {
172
173 memset(overlap, 0, sizeof(overlap));
174 memset(intersect, 0, sizeof(intersect));
175 u_char *op = &overlap[FAREA * FAREA];
176 short *ip = &intersect[FAREA * FAREA];
177
178 for (unsigned fi = FAREA; fi-- > 0; ) { /* each frame */
179 struct combostr *cbp = &frames[fi];
180 op -= FAREA;
181 ip -= FAREA;
182 int vertex = cbp->c_vertex;
183 struct spotstr *sp1 = &board[vertex];
184 int d1 = dd[cbp->c_dir];
185 /*
186 * s = 5 if closed, 6 if open.
187 * At this point black & white are the same.
188 */
189 int s = 5 + sp1->s_fval[BLACK][cbp->c_dir].c.b;
190 /* for each spot in frame A */
191 for (int i = 0; i < s; i++, sp1 += d1, vertex += d1) {
192 /* the sixth spot in frame A only overlaps if it is open */
193 int mask = (i == 5) ? 0xC : 0xF;
194 /* for each direction */
195 for (int r = 4; --r >= 0; ) {
196 struct spotstr *sp2 = sp1;
197 int d2 = dd[r];
198 /* for each frame that intersects at spot sp1 */
199 for (int f = 0; f < 6; f++, sp2 -= d2) {
200 if (sp2->s_occ == BORDER)
201 break;
202 if ((sp2->s_flags & BFLAG << r) != 0)
203 continue;
204 int n = (int)(sp2->s_frame[r] - frames);
205 ip[n] = (short)vertex;
206 op[n] |= (f == 5) ? mask & 0xA : mask;
207 if (r == cbp->c_dir) {
208 /* compute the multiple spot overlap values */
209 switch (i) {
210 case 0: /* sp1 is the first spot in A */
211 if (f == 4)
212 op[n] |= 0xA0;
213 else if (f != 5)
214 op[n] |= 0xF0;
215 break;
216 case 1: /* sp1 is the second spot in A */
217 if (f == 5)
218 op[n] |= 0xA0;
219 else
220 op[n] |= 0xF0;
221 break;
222 case 4: /* sp1 is the penultimate spot in A */
223 if (f == 0)
224 op[n] |= 0xC0;
225 else
226 op[n] |= 0xF0;
227 break;
228 case 5: /* sp1 is the last spot in A */
229 if (f == 1)
230 op[n] |= 0xC0;
231 else if (f != 0)
232 op[n] |= 0xF0;
233 break;
234 default:
235 op[n] |= 0xF0;
236 }
237 }
238 }
239 }
240 }
241 }
242 }
243