games/gomoku/makemove.c

   1 /*      $NetBSD: makemove.c,v 1.10 2009/06/04 05:43:29 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[] = "@(#)makemove.c  8.2 (Berkeley) 5/3/95";
  39 #else
  40 __RCSID("$NetBSD: makemove.c,v 1.10 2009/06/04 05:43:29 dholland Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include "gomoku.h"
  45
  46                 /* direction deltas */
  47 const int     dd[4] = {
  48         MRIGHT, MRIGHT+MDOWN, MDOWN, MDOWN+MLEFT
  49 };
  50
  51 static const int weight[5] = { 0, 1, 7, 22, 100 };
  52
  53 static void update_overlap(struct spotstr *);
  54
  55 /*
  56  * Return values:
  57  *      MOVEOK  everything is OK.
  58  *      RESIGN  Player resigned.
  59  *      ILLEGAL Illegal move.
  60  *      WIN     The winning move was just played.
  61  *      TIE     The game is a tie.
  62  */
  63 int
  64 makemove(int us, int mv)
  65 {
  66         struct spotstr *sp, *fsp;
  67         union comboval *cp;
  68         struct spotstr *osp;
  69         struct combostr *cbp, *cbp1;
  70         union comboval *cp1;
  71         int i, f, r, d, n;
  72         int space, val, bmask;
  73
  74         /* check for end of game */
  75         if (mv == RESIGN)
  76                 return(RESIGN);
  77
  78         /* check for illegal move */
  79         sp = &board[mv];
  80         if (sp->s_occ != EMPTY)
  81                 return(ILLEGAL);
  82
  83         /* make move */
  84         sp->s_occ = us;
  85         movelog[movenum - 1] = mv;
  86         if (++movenum == BSZ * BSZ)
  87                 return(TIE);
  88
  89         /* compute new frame values */
  90         sp->s_wval = 0;
  91         osp = sp;
  92         for (r = 4; --r >= 0; ) {                       /* for each direction */
  93             d = dd[r];
  94             fsp = osp;
  95             bmask = BFLAG << r;
  96             for (f = 5; --f >= 0; fsp -= d) {           /* for each frame */
  97                 if (fsp->s_occ == BORDER)
  98                     goto nextr;
  99                 if (fsp->s_flags & bmask)
 100                     continue;
 101
 102                 /* remove this frame from the sorted list of frames */
 103                 cbp = fsp->s_frame[r];
 104                 if (cbp->c_next) {
 105                         if (sortframes[BLACK] == cbp)
 106                             sortframes[BLACK] = cbp->c_next;
 107                         if (sortframes[WHITE] == cbp)
 108                             sortframes[WHITE] = cbp->c_next;
 109                         cbp->c_next->c_prev = cbp->c_prev;
 110                         cbp->c_prev->c_next = cbp->c_next;
 111                 }
 112
 113                 /* compute old weight value for this frame */
 114                 cp = &fsp->s_fval[BLACK][r];
 115                 if (cp->s <= 0x500)
 116                     val = weight[5 - cp->c.a - cp->c.b];
 117                 else
 118                     val = 0;
 119                 cp = &fsp->s_fval[WHITE][r];
 120                 if (cp->s <= 0x500)
 121                     val += weight[5 - cp->c.a - cp->c.b];
 122
 123                 /* compute new combo value for this frame */
 124                 sp = fsp;
 125                 space = sp->s_occ == EMPTY;
 126                 n = 0;
 127                 for (i = 5; --i >= 0; sp += d) {        /* for each spot */
 128                     if (sp->s_occ == us)
 129                         n++;
 130                     else if (sp->s_occ == EMPTY)
 131                         sp->s_wval -= val;
 132                     else {
 133                         /* this frame is now blocked, adjust values */
 134                         fsp->s_flags |= bmask;
 135                         fsp->s_fval[BLACK][r].s = MAXCOMBO;
 136                         fsp->s_fval[WHITE][r].s = MAXCOMBO;
 137                         while (--i >= 0) {
 138                             sp += d;
 139                             if (sp->s_occ == EMPTY)
 140                                 sp->s_wval -= val;
 141                         }
 142                         goto nextf;
 143                     }
 144                 }
 145
 146                 /* check for game over */
 147                 if (n == 5)
 148                     return(WIN);
 149
 150                 /* compute new value & combo number for this frame & color */
 151                 fsp->s_fval[!us][r].s = MAXCOMBO;
 152                 cp = &fsp->s_fval[us][r];
 153                 /* both ends open? */
 154                 if (space && sp->s_occ == EMPTY) {
 155                     cp->c.a = 4 - n;
 156                     cp->c.b = 1;
 157                 } else {
 158                     cp->c.a = 5 - n;
 159                     cp->c.b = 0;
 160                 }
 161                 val = weight[n];
 162                 sp = fsp;
 163                 for (i = 5; --i >= 0; sp += d)          /* for each spot */
 164                     if (sp->s_occ == EMPTY)
 165                         sp->s_wval += val;
 166
 167                 /* add this frame to the sorted list of frames by combo value */
 168                 cbp1 = sortframes[us];
 169                 if (!cbp1)
 170                     sortframes[us] = cbp->c_next = cbp->c_prev = cbp;
 171                 else {
 172                     cp1 = &board[cbp1->c_vertex].s_fval[us][cbp1->c_dir];
 173                     if (cp->s <= cp1->s) {
 174                         /* insert at the head of the list */
 175                         sortframes[us] = cbp;
 176                     } else {
 177                         do {
 178                             cbp1 = cbp1->c_next;
 179                             cp1 = &board[cbp1->c_vertex].s_fval[us][cbp1->c_dir];
 180                             if (cp->s <= cp1->s)
 181                                 break;
 182                         } while (cbp1 != sortframes[us]);
 183                     }
 184                     cbp->c_next = cbp1;
 185                     cbp->c_prev = cbp1->c_prev;
 186                     cbp1->c_prev->c_next = cbp;
 187                     cbp1->c_prev = cbp;
 188                 }
 189
 190             nextf:
 191                 ;
 192             }
 193
 194             /* both ends open? */
 195             if (fsp->s_occ == EMPTY) {
 196                 cp = &fsp->s_fval[BLACK][r];
 197                 if (cp->c.b) {
 198                     cp->c.a += 1;
 199                     cp->c.b = 0;
 200                 }
 201                 cp = &fsp->s_fval[WHITE][r];
 202                 if (cp->c.b) {
 203                     cp->c.a += 1;
 204                     cp->c.b = 0;
 205                 }
 206             }
 207
 208         nextr:
 209             ;
 210         }
 211
 212         update_overlap(osp);
 213
 214         return(MOVEOK);
 215 }
 216
 217 /*
 218  * fix up the overlap array due to updating spot osp.
 219  */
 220 static void
 221 update_overlap(struct spotstr *osp)
 222 {
 223         struct spotstr *sp, *sp1, *sp2;
 224         int i, f, r, r1, d, d1, n;
 225         int a, b, bmask, bmask1;
 226         struct spotstr *esp;
 227         u_char *str;
 228
 229         esp = NULL;
 230         for (r = 4; --r >= 0; ) {                       /* for each direction */
 231             d = dd[r];
 232             sp1 = osp;
 233             bmask = BFLAG << r;
 234             for (f = 0; f < 6; f++, sp1 -= d) {         /* for each frame */
 235                 if (sp1->s_occ == BORDER)
 236                     break;
 237                 if (sp1->s_flags & bmask)
 238                     continue;
 239                 /*
 240                  * Update all other frames that intersect the current one
 241                  * to indicate whether they still overlap or not.
 242                  * Since F1 overlap F2 == F2 overlap F1, we only need to
 243                  * do the rows 0 <= r1 <= r. The r1 == r case is special
 244                  * since the two frames can overlap at more than one point.
 245                  */
 246                 str = &overlap[(a = sp1->s_frame[r] - frames) * FAREA];
 247                 sp2 = sp1 - d;
 248                 for (i = f + 1; i < 6; i++, sp2 -= d) {
 249                     if (sp2->s_occ == BORDER)
 250                         break;
 251                     if (sp2->s_flags & bmask)
 252                         continue;
 253                     /*
 254                      * count the number of empty spots to see if there is
 255                      * still an overlap.
 256                      */
 257                     n = 0;
 258                     sp = sp1;
 259                     for (b = i - f; b < 5; b++, sp += d) {
 260                         if (sp->s_occ == EMPTY) {
 261                             esp = sp;   /* save the intersection point */
 262                             n++;
 263                         }
 264                     }
 265                     b = sp2->s_frame[r] - frames;
 266                     if (n == 0) {
 267                         if (sp->s_occ == EMPTY) {
 268                             str[b] &= 0xA;
 269                             overlap[b * FAREA + a] &= 0xC;
 270                             intersect[a * FAREA + b] = n = sp - board;
 271                             intersect[b * FAREA + a] = n;
 272                         } else {
 273                             str[b] = 0;
 274                             overlap[b * FAREA + a] = 0;
 275                         }
 276                     } else if (n == 1) {
 277                         if (sp->s_occ == EMPTY) {
 278                             str[b] &= 0xAF;
 279                             overlap[b * FAREA + a] &= 0xCF;
 280                         } else {
 281                             str[b] &= 0xF;
 282                             overlap[b * FAREA + a] &= 0xF;
 283                         }
 284                         intersect[a * FAREA + b] = n = esp - board;
 285                         intersect[b * FAREA + a] = n;
 286                     }
 287                     /* else no change, still multiple overlap */
 288                 }
 289
 290                 /* the other directions can only intersect at spot osp */
 291                 for (r1 = r; --r1 >= 0; ) {
 292                     d1 = dd[r1];
 293                     bmask1 = BFLAG << r1;
 294                     sp = osp;
 295                     for (i = 6; --i >= 0; sp -= d1) {   /* for each spot */
 296                         if (sp->s_occ == BORDER)
 297                             break;
 298                         if (sp->s_flags & bmask1)
 299                             continue;
 300                         b = sp->s_frame[r1] - frames;
 301                         str[b] = 0;
 302                         overlap[b * FAREA + a] = 0;
 303                     }
 304                 }
 305             }
 306         }
 307 }