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